Kristoff wants to sell his collection of shoes and offers to sell them to Marcus, who just got paid. Marcus is hesitant to accept, but Kristoff lets Marcus know that if he doesn't accept, then there may be trouble. Fearing that Kristoff means to physically harm Marcus, or rob him, Marcus accepts the offer. Will a court enforce this contract? a. No, because it is illegal to sell shoes. b. Yes, because all four requirements of a contract are present. c. No, because the consent was not voluntary. d. Yes, because there is a valid offer and acceptance.