Which of the following could result breach of fiduciary duty?

Engaging in self-dealing transactions directly results in a breach of fiduciary duty because it involves a conflict of interest where an individual places their own interests above those of their clients. A fiduciary is expected to act in the best interests of their client, maintaining loyalty and prioritizing their clients' needs and goals. When a fiduciary engages in self-dealing, they are essentially putting their personal benefit ahead of the duty they have to their clients, compromising trust and leading to a potential violation of ethical and legal standards.

In contrast, updating client files, communicating regularly with clients, and following internal compliance protocols are all essential practices that demonstrate a commitment to client service, transparency, and adherence to regulatory standards, which would not constitute a breach of fiduciary duty. These actions are indicative of a fiduciary acting responsibly and in the best interest of their clients.