Answer: B. must pay a commission of $24,000 to the listing agent.
Step-by-step explanation:
An exclusive listing agreement is a contractual agreement whereby a listing broker acts as the agent and in this case, the seller will pay a commission to the listing broker.
Since the homeowner has already signed an exclusive-listing agreement, which requires payment of 6% commission to the real estate agent but later finds a couple who purchases it for $400,000. In this case, the homeowner must still funlfil the terms of the contact and pay the listing agent the percentage that was agreed as commission and this will be:
= 6% × $400000.
= $24000
Therefore, $24000 must be paid to the listing agent.