With regard to the requirement of consideration only, which of the following would be an enforceable contract? O a. a promise by Tonya to drive a co-worker to Timmins, Ontario O b. a promise by Boris to pay $50 to Nina who found his wallet and returned it to him, even before he knew it was missing O c. a written promise, not under seal, to give Lesley $10 on Friday O d. a promise by Annik to give Katie $30 in exchange for Katie's promise to give Annik a limited edition water bottle on Saturday O e. all of the above