Which requirement is outlined in NRS 489.715 regarding offers made by dealers?

The requirement outlined in NRS 489.715 mandates that any offers made by dealers must include the disclosure of the offer terms in a signed document. This provision is crucial for ensuring transparency and protecting consumers, as it provides a written record of the terms agreed upon. By requiring that offer terms be disclosed in a signed document, the statute helps to prevent misunderstandings and disputes between the dealer and the buyer, giving both parties clear and enforceable terms surrounding the offer. This aligns with regulatory efforts to maintain ethical standards in the manufactured housing industry, ensuring fairness in transactions.

The other options do not align with the requirements set forth in NRS 489.715, as there is no stipulation that the offer terms must be verbally agreed upon, presented specifically on dealer's letterhead, or mailed to the client. The emphasis on a signed document is what distinguishes the correct answer and illustrates the importance of having a formal agreement in place.