Answer: d. Cannot accept the customer's offer
Step-by-step explanation:
Apart from the offer being unethical, the registered representative also cannot accept the customer's offer because the registered representative is prohibited from accepting cash directly from a customer.
The cash would have to be deposited in the account of the customer so as to make it more legal. Even at that however, with a limited number of shares, ethical issues come into play about how the shares can be distributed between clients so the registered representative cannot accept the customer's offer.