(a) A district shall provide 9-1-1 service to each participating county or municipality through one or a combination of the following methods and features or equivalent state-of-the-art technology:
(1) the transfer method;
(2) the relay method;
(3) the dispatch method;
(4) automatic number identification;
(5) automatic location identification; or
(6) selective routing.
(b) The district shall design, implement, and operate a 9-1-1 system for each participating county and municipality in the district.
(c) For each individual telephone subscriber in the district, 9-1-1 service is mandatory and is not an optional service under any definition of terms relating to telephone service.