A broker whose listing has expired has given the seller the names of buyers who were shown the property prior to the termination of the listing. What listing contract clause requires this action if the brokerage is to earn a commission on a later sale to one of the named buyers?

The due diligence clause refers to the responsibilities of the buyer or seller to conduct thorough research and investigation regarding the property. While important, it does not pertain to the broker's entitlement to commission or the obligation to inform sellers about prospective buyers after a listing has ended.

The procuring cause clause relates to the broker's role in being the primary agent responsible for bringing about a sale. While it is relevant in determining commission entitlement, it does not specifically require the broker to provide a list of buyers after the listing has expired, which is the focus of the protection clause.

The MLS permission clause pertains to the permissions and requirements for listing a property on the Multiple Listing Service. It does not address the broker's rights regarding commission on sales to buyers who were shown the property prior to the expiration of the listing.