An investor purchased a bond as a long-term investment on January 1. Annual interest was received on December 31. The investor's interest income recorded would decrease each year if the bond were purchased at: Select one: a. Par b. A discount, and the straight-line method was used O c. A discount, and the effective method was used d. A premium, and the effective method was used e. A premium, and the straight-line method was used Clear my choice