Which action is prohibited for a trustee under duties against self-dealing?

The action of buying trust assets for personal use is prohibited for a trustee under the duties against self-dealing because it creates a clear conflict of interest. Trustees have a fiduciary duty to act in the best interests of the trust and its beneficiaries, which includes the obligation to avoid any transactions that could benefit themselves at the expense of the trust. When a trustee purchases trust assets for their personal use, it undermines this duty, as the trustee has a personal financial interest in the transaction that may not align with the interests of the beneficiaries.

In contrast, making prudent investments, charging a fee for trustee services, and taking advice from investment consultants are all actions that are permissible under the trustee's duties, provided they align with the best interests of the beneficiaries and comply with relevant laws and trust terms. For example, prudent investments are necessary for trust management, and charging reasonable fees for services is typically acceptable if disclosed to the beneficiaries. Seeking advice from professionals can enhance the trustee's decision-making and is often encouraged.