Which of the Following Statements Best Describes Sinking Funds

Which of the following statements best describes sinking funds?

A) Sinking fund provisions sometimes turn out to adversely affect bondholders, and this is most likely to occur if interest rates decline after the bond has been issued.
B) Most sinking funds require the issuer to provide funds to a trustee, which saves the money so that it will be available to pay off bondholders when the bonds mature.
C) A sinking fund provision makes a bond more risky to investors at the time of issuance.
D) Sinking fund provisions never require companies to retire their debt; they only establish "targets" for the company to reduce its debt over time.