After December 1, 1987, the Secretary of Housing and Urban Development shall control rents and charges as they were controlled prior to April 19, 1983, for any multifamily housing project insured under the National Housing Act [12 U.S.C. 1701 et seq.] if—

(1) during the period of April 19, 1983, through December 1, 1987, the project owner and the Secretary have not executed, and the project owner has not filed a written request with the Secretary to enter into, an amendment to the regulatory agreement pursuant to regulations published by the Secretary on April 19, 1983, or June 4, 1986, electing to deregulate rents or utilize an alternative formula for determining the maximum allowable rents pursuant to regulations published by the Secretary on April 19, 1983, or June 4, 1986; and

(2)(A) the project was, as of December 1, 1987, receiving a housing assistance payment under a contract pursuant to section 1437f of title 42 (other than under the existing housing certificate program of section 1437f(b)(1) of title 42); or

(B) not less than 50 percent of the units in the project are occupied by lower income families (as defined in section 1437a(a)(2) ¹ of title 42).