Which of the Following Is Not a Difference Between Municipal

Which of the following is not a difference between municipal bonds (munis) and corporate bonds?

A) Interest paid on munis is tax-exempt, while interest paid on corporate bonds is not.
B) Munis often have a range of maturities (are serial issues) but corporate bonds do not.
C) Unlike corporate bonds, munis are rated by bond-rating agencies such as Moody's.
D) All of the above are differences between munis and corporate bonds.