One of the statements is true. What is it?

a. If two bonds have the same duration, the changes in their price for the same changes in interest rates will be the same.

b. Treasury bonds have reinvestment risk.

c. Investors who purchase convertible bonds can expect reinvestment risk after the bonds are converted to equity.

d. A sinking fund provision in a bond increases the required rate of return of the bond if other factors are constant.