Treasury bills (T-bills) are short-term debt securities issued at a discount to par value. The difference between the purchase price and the par value represents the investor’s interest income, which is realized when the T-bill matures.

C is correct because T-bills are issued at a discount and mature at par.

A is incorrect because T-bills are not sold at par value.

B and D are incorrect because T-bills do not pay periodic interest; the return is based on the discount.