The membership of such association shall consist solely of the following or any combination thereof:
- (a) Members of police departments of municipal or public corporations or districts.
- (b) Members of fire departments of municipal or public corporations or districts.
- (c) Peace or law enforcement officers who are regular and salaried officers or employees of the state or of a single county or other political subdivision or public or municipal corporation.
- (d) Persons who are emergency medical services personnel and employed by a fire department of a city, county, or district.
- (e) Persons who at the time of becoming members of such association were qualified pursuant to subdivisions (a), (b), (c), or (d) of this section.