If a broker forgets about a deadline for a contingency that protects their client, the broker is in violation of their fiduciary duty of:

The correct answer, which pertains to the duty of care, highlights the obligation that brokers have to act competently and diligently when managing their clients' affairs. In the context of a real estate transaction, this includes being aware of and adhering to deadlines for contingencies that protect the client's interests. By forgetting a deadline, the broker fails to exercise the necessary level of skill and attention that a reasonably competent broker would provide.

This violation not only impacts the client’s position in the transaction but also reflects a lack of professionalism and commitment to safeguarding the client’s best interests. The duty of care emphasizes the importance of being proactive and attentive to details that could significantly affect the outcome for a client. Meeting deadlines is a crucial part of this responsibility.

While disclosure, loyalty, and accounting are also important fiduciary duties, they do not directly address the specific scenario of failing to meet deadlines. Therefore, the violation of duty in this case clearly aligns with the duty of care, making it the most relevant choice.