Final answer:
Each written offer a Salesperson receives is indeed considered a separate offer and is required to be retained by the seller's brokerage for six years if accepted or one year if unaccepted or countered, in compliance with real estate regulations.
Step-by-step explanation:
For every written offer that a Salesperson receives on behalf of a seller, whether it is a buyer's first offer or an offer with changes made during negotiations, the question states that the offer is considered a separate offer and a seller's brokerage is required to retain a copy for six years when the offer is accepted or for one year for the unaccepted or countered offer in entirety. The statement is True. Each written offer received must be retained appropriately according to real estate law and regulations, which typically mandate records to be kept for a specified duration to ensure a clear transaction history and for potential future disputes or audits.