Kit Offers to Sell Her Boat to Liu

Kit offers to sell her boat to Liu. Liu accepts and, unknown to Kit, builds a dock for the boat. Kit's later attempt to revoke the offer will be

A) effective because Kit did not build the dock.
B) effective because Kit did not know that Liu would build a dock.
C) ineffective because Liu justifiably relied on Kit's offer.
D) ineffective because Liu showed a serious intent to close the deal.