Final answer:
The Illinois Residential Real Property Disclosure Report should be accurately completed by the seller, who is responsible for informing potential buyers about the property's condition. Seller's agents and attorneys may aid in the process, but completing the report is the seller's legal duty.
Step-by-step explanation:
The Illinois Residential Real Property Disclosure Report should be completed by the seller. This document, which is required by law, is designed to inform potential buyers about the condition of the property for sale. The seller has firsthand knowledge of the history and issues of the property, and thus it is their responsibility to complete the disclosure form honestly and accurately. While the seller's agent might assist in ensuring that the form is completed, it is ultimately the seller's obligation to provide this disclosure. It is not the responsibility of the seller's attorney, although the attorney may review the document to ensure it meets legal requirements.