OPINION — AG — QUESTION: "IS THE NATIONAL CHURCH FOUNDATION EXEMPT FROM PAYING MORTGAGE TAX UPON BONDS SECURING AN INDEBTEDNESS OF $25,000 OWED TO SUCH FOUNDATION BY ONE OF YOUR LOCAL CHURCHES?" — NEGATIVE CITE: 68 O.S. 1961 1173 [68-1173], 68 O.S. 1961 1171-1182 [68-1171] — [68-1182], 68 O.S. 1961 1172 [68-1172], 68 O.S. 1961 15.2 [68-15.2], ARTICLE X, SECTION 6 (W. J. MONROE)