A broker entered into a listing contract with the seller of a house and became the single agent of the seller. A potential buyer wants to see the seller's house and wishes to have representation by the broker as well. The broker must

A$.$ disclose in writing to a buyer that the licensee is an agent of seller.

B$.$ have the seller sign a Transition to Transaction Broker form before showing the house to the buyer.

C$.$ deliver a copy of the Agency Disclosure Form to the seller.

D$.$ get the informed, written consent of all parties prior to becoming a dual agent.