provide services under this division to at least one grade level of students, beginning not later than 7th grade, in a participating school that has a 7th grade and in which at least 50 percent of the students enrolled are eligible for free or reduced-price lunch under the Richard B. Russell National School Lunch Act [
42 U.S.C. 1751 et seq.] (or, if an eligible entity determines that it would promote the effectiveness of a program, an entire grade level of students, beginning not later than the 7th grade, who reside in public housing as defined in
section 1437a(b)(1) of title 42);