Which is NOT a requirement of the NCHADFB concerning consumer sales?

The correct choice highlights that the collection of personal data for marketing purposes is not a requirement set forth by the NCHADFB in the context of consumer sales. The NCHADFB emphasizes consumer protection and ensuring that clients are adequately informed about the products and services they receive, but it does not mandate that hearing aid dealers and fitters collect personal data specifically for marketing reasons.

On the other hand, documentation of service agreements, transparency on pricing and discounts, and provision of warranty information are all critical aspects designed to ensure that consumers understand their rights, the costs incurred, and the services provided. These requirements are aimed at promoting honesty and clarity in transactions within the hearing aid market, which is vital for maintaining consumer trust and protecting their interests.