A. If no municipal corporation is included within the boundaries of a district comprising all or part of a single parish, the parish governing authority may be the governing body of the district or may appoint a board of commissioners to serve as the governing body for the district.
B.(1) If a municipal corporation is included within the boundaries of a district, or if the boundaries of a district comprise all or part of two or more parishes, the governing body of the district shall consist of a board of commissioners of the district.
(2) However, the parish governing authority may in its discretion continue to be the governing body of the district in those instances where a municipal corporation lying within the boundaries of the district is created after the creation of the district and after 1970.