Which of the following is classified as a discontinued debt instrument?

A treasury bill is classified as a discontinued debt instrument because it is a short-term debt obligation issued by the government. Treasury bills, or T-bills, are sold at a discount to their face value and do not pay periodic interest. Instead, the investor receives the face value upon maturity, which can range from a few days to one year.

This characteristic differentiates treasury bills from other types of debt instruments that might have ongoing interest payments or longer-term commitments. They are essentially considered discontinued because once they mature, they do not have a secondary income stream like traditional bonds, and new treasury bills are issued periodically as part of government financing.

Mortgage bonds, futures contracts, and option contracts do not fit this classification because they either represent ongoing financial obligations (like mortgage bonds) or are derivative products that do not constitute direct debt instruments in the same manner as treasury bills.