What must Salesperson A ensure is completed before the listing may proceed, according to regulatory standards?

The correct answer is that Salesperson A must ensure the completion of the Real Estate Condition Report before the listing may proceed, according to regulatory standards. This report is crucial as it provides potential buyers with essential information about the property's condition, ensuring transparency and helping to avoid disputes regarding the property's state after the sale. Regulatory standards often mandate that sellers complete this report to disclose any known issues or defects, which is a protective measure for both buyers and sellers in the real estate transaction process. By having this document in place, Salesperson A ensures compliance with regulations, which fosters trust and legal integrity in the transaction.

The other options listed do not align with the regulatory requirements necessary for progressing with a property listing. For example, inspecting a property after a written offer may happen at a different stage of the transaction process and does not serve as a prerequisite for listing. Hosting a public open house and obtaining approval from buyers also relate to different aspects of the real estate process that occur after the listing is established.