Final answer:
According to the fiduciary duty of obedience, an agent must follow the principal's lawful instructions and is not required to obey unlawful instructions or instructions deemed personally irrelevant.
Step-by-step explanation:
The fiduciary duty of obedience requires that an agent must follow the lawful instructions of their principal. This means that the correct answer to the question is that according to the fiduciary duty of obedience, the agent must obey lawful instructions from the principal. Unlawful instructions, or instructions that the agent personally believes to be irrelevant, are not included in this duty. An agent's responsibility is to act in the principal's best interest within the legal framework. Therefore, the agent does not have the discretion to choose which lawful instructions to follow based on their relevance, nor are they permitted to obey instructions that are illegal.