An expired listing broker gives the seller the names of prior prospective buyers. What clause obligates the seller to pay a commission if one of those buyers later purchases the property?

A due-diligence clause typically relates to the buyer's right to conduct investigations regarding the property before finalizing the purchase. It does not address the broker's commission or the seller's obligation to compensate the broker based on previous buyers, making it irrelevant in this context.

The procuring cause clause pertains to determining which broker is entitled to a commission based on who was responsible for bringing the buyer to the table. While it addresses commission rights, it does not specifically cover the scenario of an expired listing and the obligation to pay for previous buyers as defined by a protection clause.

An MLS permission clause generally involves the terms under which a property is listed in a Multiple Listing Service, including permissions and restrictions related to the listing. This clause does not relate to commission obligations or prior prospective buyers, thus making it irrelevant to the question at hand.