On Day 1, Janet makes an offer to sell her business to Ben for $200,000. Ben does not want to accept the offer immediately because he is also looking at a few other businesses. After some negotiations, Janet and Ben sign a written agreement. Under the agreement, Janet will keep her offer open until the end of Day 30 and Ben will pay Janet $500 for that. Ben pays Janet the $500 on Day 3. On Day 10, Tracey offers to buy Janet's business for $250,000, and Janet immediately accepts the offer. On Day 11, Janet tells Ben that she withdraws her offer made to him, and tries to return the $500 to Ben. But Ben refuses to accept the money. On Day 12, Ben tells Janet that he accepts her offer made on Day 1.

Which of the following statements best describes the legal position?

A) Janet validly revokes her offer on Day 11 because it takes too long for Ben to accept (finally on Day 12) her offer.

B) Janet validly revokes her offer on Day 11 because she tries to return the $500 to Ben.

C) There is a contract between Janet and Ben under which Janet must sell the business to Ben.

D) There can be no contract between Tracey and Janet for the sale of the business