The correct answer is: B. corporate bonds.
A corporate bond is a debt instrument issued by a corporation. It is a loan that the corporation makes to an investor, and the investor agrees to pay the corporation interest on the loan for a specified period of time. The corporation then repays the loan at the end of the specified period.
Municipal bonds are debt instruments issued by state and local governments. They are considered to be tax-exempt, which means that the interest earned on them is not subject to federal income tax. This makes them attractive to investors who are looking for a tax-advantaged investment.
U.S. Treasury bonds are debt instruments issued by the U.S. government. They are considered to be the safest investment in the world, and they are considered to be a benchmark for other investments.
Mortgages are loans that are secured by real estate. They are typically used to finance the purchase of a home, but they can also be used to finance other types of real estate investments.
In conclusion, the correct answer is: B. corporate bonds.