(A) The commission must be composed of twenty-one members in accordance with federal law appointed by the governing bodies of the counties enumerated in § 43-41-40 and must be so constituted that:

(1) one-third of the members of the commission are elected public officials or their representatives, unless the number of these officials reasonably available or willing to serve is less than one-third of the membership of the commission;

(2) at least one-third of the members are persons chosen in accordance with democratic selection procedures adequate to assure that they are representative of the poor in the areas served; and

(3) the remainder of the members are officials or members of business, industry, labor, religious, welfare, education, or other major groups and interests in the areas served.

(B) The commission may increase in multiples of three in the total membership if necessary to comply with § 43-41-80 or to meet additional federal requirements.

(C) If the commission membership is increased under § 43-41-80, the three new seats must be apportioned by the commission among the participating counties, to include a seat for the petitioning group, according to federal regulatory measures promulgated under federal law.