Should all members of the governing body, including all standby members, be unavailable, temporary officers shall be appointed to serve until a regular member or a standby member becomes available or until the election or appointment of a new regular or standby member. Temporary officers shall be appointed as follows:
(a) By the chairman of the board of supervisors of the county in which the political subdivision is located, and if he is unavailable,
(b) By the chairman of the board of supervisors of any other county within 150 miles of the political subdivision, beginning with the nearest and most populated county and going to the farthest and least populated, and if he is unavailable,
(c) By the mayor of any city within 150 miles of the political subdivision, beginning with the nearest and most populated city and going to the farthest and least populated.
(Added by Stats. 1970, Ch. 1454.)