Answer:
An exclusive agency
Step-by-step explanation:
An exclusive agency gives one broker the exclusive right to sell a particular property, though they may agree to pay a portion of their sales commission to a broker who procures a buyer. An exclusive agency agreement allows the seller to sell the property directly and not have to pay a commission to the listing broker.
This protection lets the agent receive full commission, in case the buyer they brought changes their mind and comes back later, after the agreement has expired.