Which of the following actions is a breach of a director's duty?

Accepting undisclosed benefits from outside parties constitutes a breach of a director's duty because it violates the principle of loyalty and fiduciary duty that directors owe to the company and its shareholders. Directors are expected to act in the best interests of the company, avoiding situations where personal interests conflict with their obligations to the company. When a director accepts undisclosed benefits, it creates a potential conflict of interest, undermining trust and potentially harming the company's reputation and financial standing.

In contrast, exercising independent judgment, promoting the success of the company, and declaring an interest in a proposed transaction are all aligned with a director's responsibilities. Independent judgment is a vital aspect of a director's role, allowing them to make decisions based on what is best for the company. Promoting the success of the company is a fundamental duty, encompassing strategic decisions that foster growth and profitability. Declaring an interest in a proposed transaction is also essential as it ensures transparency and helps prevent conflicts of interest, which are key components of good corporate governance.