(a) The municipal authority responsible for approving plats under this subchapter is the municipal planning commission or, if the municipality has no planning commission, the governing body of the municipality. The governing body by ordinance may require the approval of the governing body in addition to that of the municipal planning commission.
(b) In a municipality with a population of more than 1.5 million, at least two members of the municipal planning commission, but not more than 25 percent of the membership of the commission, must be residents of the area outside the limits of the municipality and in which the municipality exercises its authority to approve subdivision plats.