A Homeowner Desires to Sell His or Her Home and Signs

A homeowner desires to sell his or her home and signs an exclusive-listing agreement, requiring  payment of a six percent commission to the real estate agent. If shortly thereafter, but before the  agent has time to do anything to sell the property, the owner surprisingly finds a couple who  purchases it for $400,000, the homeowner ​

A) must pay $24,000 to the listing agent.
B) is legally required only to reimburse the agent for out-of-pocket expenses.
C) has lucked out and need not pay any commission to the agent, because the agent hadn't done anything yet.
D) must pay the $24,000 commission only if the agent had acted with due diligence by placing the listing in the local multiple-listing service.