A 401(k) Plan Administrator must be aware of any potential conflicts of interest when making decisions with respect to the plan. This includes avoiding self-dealing and ensuring that any fees charged by third-party service providers are reasonable and disclosed to participants in a transparent manner. Additionally, fiduciaries should avoid taking risks that could lead to losses or liabilities for the plan. By understanding these responsibilities and avoiding potential conflicts of interest, 401(k) plan administrators can ensure that they act in their beneficiaries' best interests and fulfill their fiduciary duties.