not sure if im right, help please! thank u

What explicit tax rate would keep Orlando indifferent between purchasing a municipal bond with a 4.0 percent return and a taxable bond with a 5.5 percent before-tax return? Multiple Choice O 25.0% 27.3% 31.2% 33.5% O None of the choices are correct. ***** If Rachel has a 37% tax rate and a 10% after-tax rate of return, a $100,000 tax deduction in one year will save how much tax in today's dollars (rounded)? (Exhibit 3-1) Multiple Choice . $100,000 O $37.000 O $36,040 $33,633 None of the choices are correct Assume that Bill's marginal tax rate is 37%. If corporate bonds pay 10% interest, what interest rate would a municipal bond have to offer for Bill to be indifferent between the two bonds? Multiple Choice O 10.00% O 1587% 8.00% 6.30% None of the choices are correct