You are advising a client in the 32% total tax bracket who is interested in buying a tax-free security at 4.50% for 10 years. You also show her a taxable security at par with a 6.65% coupon for 10 years, and a zero- coupon bond for 10 years at a price of $52, with a $100 par. All these instruments pay interest annually and have identical credit risk, so which is she most likely to buy? (Show the work)