(a) County boards of education shall provide sufficient personnel, equipment, and facilities as will ensure that each first through sixth grade classroom, or classrooms having two or more grades that include one or more of the first through sixth grades shall not have more than 25 pupils for each teacher of the grade or grades and shall not have more than 20 pupils for each kindergarten teacher per session, unless the state superintendent has excepted a specific classroom upon application therefor by a county board.
(b) County school boards may not maintain a greater number of classrooms having two or more grades that include one or more of the grade levels referred to in this section than were in existence in said county as of January 1, 1983.
(c) The state superintendent is authorized, consistent with sound educational policy, to:
(1) Permit on a statewide basis, in grades four through six, more than 25 pupils per teacher in a classroom for the purposes of instruction in physical education; and