On February 3, 1974, members of the Waterloo police department executed a search warrant at defendant’s Cedar Falls home. While the warrant specified heroin (see § 751.5, The Code), the only controlled substance found was a quantity of marijuana. The search also produced a kilo scale, two “dime bags” and some “nickel bags” of marijuana, a plastic bag of “poorly manicured” marijuana, germinating marijuana seeds, a mortar and pestle, and other items. No roach clips, roach pipes, papers or other smoking paraphernalia were found. There was no odor of marijuana in the premises.
Upon jury trial defendant was convicted of possession of a controlled substance with intent to deliver, in violation of § 204.401(1), The Code. He then requested and was granted a hearing under § 204.409(2), The *38Code, to determine if he was “addicted to, dependent upon, or a chronic abuser of” a controlled substance and should therefore receive medical or rehabilitative treatment. Trial court denied such relief. Defendant appeals following his sentence to a term not to exceed five years in the penitentiary. We affirm.
I. Defendant asserts trial court erred by allowing a police officer to opine, in response to a hypothetical question, that the marijuana seized was being held for delivery.
Captain Dolan of the Waterloo police department narcotic division was asked a hypothetical question incorporating an itemization of all property seized in defendant’s home, and the fact no smoking paraphernalia was found. Inquiry was then made if he had an opinion whether the marijuana was for personal use or for sale. After responding he did have an opinion, Dolan, over objection, was allowed to state, “My opinion would be that the marijuana was being held for delivery or to be delivered.”
In this case expert testimony relating to the manner in which marijuana is ordinarily packaged for sale and the differ-entiative devices and paraphernalia customarily used in sale or in consumption of this substance was properly admitted into evidence and may have aided the jury. See State v. Boyd, 224 N.W.2d 609, 613 (Iowa 1974); State v. Lynch, 197 N.W.2d 186, 190 (Iowa 1972), cert. denied 409 U.S. 1116, 93 S.Ct. 916, 34 L.Ed.2d 700 (1973).
But the combined question and response at issue plainly crossed that “fine but essential” line between opinion which would be truly helpful to the jury and that which merely conveys a conclusion concerning defendant’s legal guilt. See State v. Johnson, 224 N.W.2d 617, 622 (Iowa 1974); State v. Hines, 223 N.W.2d 190, 192-193 (Iowa 1974).
We therefore must determine whether the issue raised here was properly preserved below. Defendant’s objection was,
“[T]he hypothetical does not assume all of the facts in the record. And it assumes facts, again, that are not in the record. For the further reason that this calls for an opinion and conclusion of the witness, no proper foundation laid. It’s based on hearsay testimony.”
Some specific reason for the exclusion of opinion evidence must be stated. It is the duty .of counsel to point out the particular defect or defects. Fischer, Inc. v. Standard Brands, Inc., 204 N.W.2d 579, 583 (Iowa 1973); Twin-State Eng. & Chem. Co. v. Iowa State Hwy. Com’n, 197 N.W.2d 575, 581 (Iowa 1972). The generalized objections interposed here were inadequate to apprise the court of any valid ground for excluding this opinion. State v. Whitfield, 212 N.W.2d 402, 410 (Iowa 1973); State v. Buchanan, 207 N.W.2d 784, 788 (Iowa 1973); see generally State v. Hines, supra. We find no reversible error on this facet of the case.
II. Defendant complains trial court abused its discretion in denying him chronic abuser treatment under § 204.409(2), The Code.
Section 204.409(2) provides, inter alia:
“Whenever the court finds that a person who is charged with a violation of section 204.401 and who consents thereto, or who has entered a plea of guilty to or been found guilty of a violation of said section, and who is addicted to, dependent upon, or a chronic abuser of any controlled substance and that such person will be aided by proper medical treatment and rehabilitative services, it may order that he be committed as an in-patient or out-patient to a facility approved by the state department of health for such medical treatment and rehabilitative services. * * * ” (Emphasis supplied.)
At the post-trial hearing defendant testified he had used marijuana since 1969, he smoked two marijuana cigarettes per day *39when not working and less when employed, he depended on it, he had “not quite” been able to stop, a counselor told him stopping would depend on him and it would help to be around non-users or use a drug council program, he never smoked at work, and he recently had reduced his usage. A friend testified defendant smoked marijuana every day.
Trial court also had before it a pre-sen-tence investigation report. This document had been examined by defendant and his counsel. Defense counsel stated there were no suggested additions or corrections. The report carried a “rap sheet” detailing defendant’s long involvement in law breaking, including a felony conviction.
These parties agree the statutory use of the word “may” in § 204.409(2) lodges discretion in trial court to grant or withhold treatment. See § 4.1(36), The Code; John Deere Waterloo Tractor Works v. Derifield, 252 Iowa 1389, 1392, 110 N.W.2d 560, 562 (1961). Other statutory language makes clear the court’s discretion is exercised only after a finding that 1) addiction, dependency or chronic abuse exists and 2) the defendant will be aided by proper medical treatment and rehabilitative services.
Defendant’s testimony in the post-trial hearing was vague and ambiguous. In any event, trial court was not obligated to accept it as true. See State v. Deanda, 218 N.W.2d 649, 652 (Iowa 1974); Jordan v. Sinclair Refining company, 257 Iowa 813, 822, 135 N.W.2d 120, 125 (1965).
Defendant seeks to finesse these problems by arguing failure of trial court to express its reason for denying treatment and imposing sentence makes that disposition, on its face, an abuse of discretion, citing McCleary v. State, 49 Wisc.2d 263, 281-282, 182 N.W.2d 512, 522 (1971).
In McCleary the Wisconsin Supreme Court adopted Standard 2.3(c) of the American Bar Association Standards Relating to Appellate Review of Sentences. This standard requires the sentencing judge to state his reasons for selecting the particular sentence imposed.
Without question, articulation of the rationale undergirding a sentence would assist both trial court and the appellate court on review. However, even the McCleary court, although stating the naked sentence “appears [to be] * * * the product of an abuse of discretion in that there was no delineation of any of the factors utilized by the trial judge in the exercise of discretion,” recognized its obligation on review “to search the record to determine whether in the exercise of proper discretion the sentence imposed can be sustained.” State v. McCleary, supra; see State v. Banks, 213 N.W.2d 483, 486 (Iowa 1973); State v. Davis, 195 N.W.2d 677, 678 (Iowa 1972).
We have examined the record to determine whether it discloses an abuse of discretion vel non. We have already noted the quality of the evidence before trial court. The trial court well could have rejected defendant’s testimony he was dependent upon marijuana, or concluded he would not be “aided by proper medical and rehabilitative services.” Defendant sought no aid until after conviction. Trial court could reasonably find the principal remedial device recommended in the testimony — segregation from users — could hopefully be accomplished as well in prison as in a rehabilitation center.
Finally, trial court may have been influenced by the presentence report which amply supports a conclusion defendant should be under the higher-security detention of a penal institution rather than treatment in a medical facility. The report did not recommend probation because defendant’s record indicated he was a poor security risk.
We find no abuse of discretion. The sentence is affirmed.
Affirmed.
MOORE, C. J., and LeGRAND, REES, UHLENHOPP and HARRIS, JJ., concur. *40McCORMICK, MASON and RAWLINGS, JJ., concur specially.