15. On January 1, Karl offered to sell his neighbor Bobby his lawn mower for $400. Bobby was considering whether to purchase the lawn mower, but told Karl, "I cannot decide whether I want to buy your lawn mower. If I pay you $10.00 will you leave the offer open until January 5?" The men agreed and Bobby paid the Karl $10.00. On January 2, Bobby told Karl, "I am not going to buy the mower. Karl, however, did not take any steps to sell the mower to someone else. On January 3, Bobby told Karl he would go ahead and buy the mower for the price they had discussed. Is there an enforceable contract between the two at this point? O O A. No, because the January 3 statement constituted a counteroffer. O B. No, because $10.00 is not considered to be adequate consideration to hold open an offer. O C. Yes, because Karl did not take any steps in reliance on Bobby's January 2 rejection Karl had accepted the offer prior to the January 5 deadline. O D. Yes, because an option contract can always be accepted during the time period that the offer is held open.16. Bob wrote an email to Sam on November 1st telling him he is interested in purchasing a 1950's hot-rod that Sam had advertised for sale online. Bob's email to Sam stated: "If I don't hear from you by November 15th, my offer will expire. Did Bob make a valid offer that Sam could accept