Suppose the money supply grew at an average annual rate of 8%, velocity was constant, the nominal interest rate averaged 9%, and output grew at an average annual rate of 3%. according to the quantity theory, a. inflation averaged 8% per year and the real rate of return was 9%. b. inflation averaged 11% per year and the real rate of return was 17%. c. inflation averaged 5% per year and the real rate of return was 4%. d. inflation averaged 1% per year and the real rate of return was 6%.