Final answer:
The seller must pay a commission to both the first broker, due to the open listing agreement, and the second broker, due to the exclusive right-to-sell listing, assuming it was still in effect when the first broker found a buyer.
Step-by-step explanation:
If a seller has an open listing agreement with a broker, they are free to hire other brokers at the same time. However, should the seller enter into an exclusive right-to-sell listing with a second broker, the terms of that agreement typically require the seller to pay the exclusive broker a commission, regardless of who finds the buyer. If the first broker produces a buyer for the property whose offer the seller accepts, under an open listing, the seller would typically owe a commission to the first broker. However, the existence of the subsequent exclusive right-to-sell listing complicates this scenario, potentially obligating the seller to also pay a commission to the second broker.
Given these facts, the most accurate answer would be C. both brokers. The seller must pay the first broker because they were hired under an open listing and produced a buyer, and must also pay the second broker because of the exclusive listing agreement, assuming it was still in effect at the time of the sale.