Answer:
c. at a discount.
Step-by-step explanation:
If the market interest rate is greater than the contractual rate of interest, the bond will sell at a discount. It means that the bond is selling at a rate less than its par value.
If the market interest rate is less than the contractual rate of interest, the bond will sell at a premium. It means that the bond is selling at a rate higher than its par value.
If the market interest rate is equal to the contractual rate of interest, the bond will sell at par or at face value.