(c) Requirements concerning trustees. The trustee or trustees referred to in paragraphs (a) and (b) shall be either named in the trust instrument or in the plan instrument described in
section 402(a) of the Act, or appointed by a person who is a named fiduciary (within the meaning of
section 402(a)(2) of the Act). Upon acceptance of being named or appointed, the trustee or trustees shall have exclusive authority and discretion to manage and control the assets of the plan, except to the extent that:
(1) The plan instrument or the trust instrument expressly provides that the trustee or trustees are subject to the direction of a named fiduciary who is not a trustee, in which case the trustees shall be subject to the proper directions of such fiduciary which are made in accordance with the terms of the plan and which are not contrary to the provisions of title I of the Act of chapter XXV of this title, or