A couple desperately wants to move to Pine Bend, and they like the seller's house, which is listed with a broker. The couple tells the broker they will "make it worth his while" if he can persuade the sellers to accept their offer, and they send an expensive food basket to the broker as a sign of their good faith. The broker neglects to mention this to the sellers. This practice is a. acceptable. b. mandated. c. discouraged. d. prohibited.