Please explain.

Under the effective interest method that is required under GAAP to account for bonds, the periodic interest expense is a. the stated rate of interest multi plied by the face value of the bonds b. the effective rate of interest multiplied by the face value of the bonds. c. the stated rate of interest multiplied by the beginning-of-period carrying value of the bonds d. the effective rate of interest multi plied by the be ginning-of- period carrying value of the bonds