16. The following yields were reported on August 4, 2014, for U.S. Treasury secure corporate bonds, and tax-exempt bonds (i.e., municipal bonds): Issuer Rating Treasury Corporate AAA Corporate AA Corporate | . Tax exempt | AAA Tax exempt AA Tax exempt A 2-Year 0.52 - 0.52 0.65 5-Year 1.75 1.87 2.02 2.12 1.15 1.30 1.47 10-Year 2.56 2.92 3.26 3.42 2.15 2.44 2.42 0.42 0.43 0.63 a. Why is the yield on a tax-exempt security less than the yield on a Treasury secu- rity of the same maturity and credit rating? b. Why is the yield on a tax-exempt security less than the yield on a corporate secu- rity of the same maturity and credit rating? C. What appears to be the relationship between yield and maturity for corporate bonds? d. For an investor in the 40% marginal tax bracket, compare the yield on the two- year AA-rated corporate bond and the tax-exempt bond on an equivalent taxable yield basis