18) Caterer agrees with Bride to cater Bride's wedding reception for $12 per plate. On the wedding day, Caterer calls Bride saying that some things have come up, and she will have to charge $16 a plate in order to do the catering. Bride agrees. Which is true? a. The $16 is not enforceable because the $12 per plate was past consideration. b. The $16 is not enforceable because of a preexisting duty. c. The $16 is enforceable if the reason for it was beyond Caterer's control. d. The $16 is not enforceable because it means the $12 was an illusory promise. e. The $16 is enforceable if Bride could have found another caterer before the wedding.