What signifies a "breach of fiduciary duty"?

A breach of fiduciary duty occurs when an individual fails to act in the best interests of another party, typically in a professional relationship where trust and confidence are paramount. The correct answer highlights a scenario where an agent prioritizes their interests over those of the client, which directly undermines the fundamental principle of fiduciary duty.

In a fiduciary relationship, the agent is expected to act loyally and in good faith for the benefit of the client. When the agent's actions reflect self-interest, it constitutes a clear violation of this duty, potentially leading to legal repercussions or the loss of trust.

The other options describe situations that may involve issues in client relationships or contracts, but they do not encapsulate the essence of a fiduciary breach. For example, failing to disclose personal interests or making errors in valuations, while potentially harmful, do not inherently reflect the more severe ethical lapse of putting personal gains ahead of a client’s needs.