Mr. Brown is in the 10 percent federal income tax bracket and wants to invest $10,000 in interest-earning assets. Mr. Black is in the 35 percent bracket and wants to invest $15,000. The current rate on a typical high- quality tax exempt municipal bond is 3.5 percent and on a high-quality corporate bond is 4 percent. You are the financial advisor to both. Which investment would you recommend to each individual?