Final answer:
The broker should refuse to commit an unlawful act and inform the client of the legal consequences.
Step-by-step explanation:
The correct action the broker should take when the client wants them to commit an unlawful act is Option B: Refuse to commit the unlawful act and advise the client of the legal consequences of doing so. Brokers have a duty to follow their clients' instructions, but this duty is not absolute. If the client's instructions involve an illegal activity, the broker is obligated to refuse and inform the client about the potential legal ramifications. By refusing to commit the unlawful act, the broker upholds their professional integrity and acknowledges the importance of adhering to the law.