No fiduciary shall cause any assets of a plan to be invested in any covered entity (as defined in section 12(d)(6)(B) of the Investment Company Act of 1940 ( 15 U.S.C. 80a–12(d)(6)(B) )). . (4) Effective date (A) In general Except as provided in subparagraph (B), the amendments made by this subsection shall apply to plan years beginning after the date which is 180 days after the date of the enactment of this Act. (B) Plan amendments If subparagraph (C) applies to any retirement plan or contract amendment— (i) such plan or contract shall not fail to be treated as being operated in accordance with the terms of the plan during the period described in subparagraph (C)(ii) solely because the plan operates in accordance with the amendments made by this subsection