An offer to purchase becomes a binding contract when the

O A.seller mails the signed offer to the buyer's agent after making a price adjustment.

O B.seller signs the buyer's offer and the listing agent communicates it to the buyer's agent.

O C. listing agent emails the buyer's agent that the seller agrees to the buyer's offer as written.

O D. listing agent tells the buyer's agent that the seller agrees to all but one term on the buyer's offer.