A department store sells gift certificates that are redeemable for merchandise. Each certificate expires three years after the date of issuance. The revenue from the gift certificates should be recognized: O a. In the period the certificates are redeemed or in the period in which they expire if they are allowed to lapse. O b. Evenly over the three years from the date of issuance. O c. In the period in which the certificates are sold. O d. In the period in which the certificates expire.