Public offices and party offices and public questions shall be divided and classified as follows:
a. Those offices voted for and public questions voted upon by the electors of the state or of more than one county thereof, or members of the house of representatives;
b. Those offices voted for and public questions voted upon by the electors of a county or of more than one municipality thereof;
c. Those offices voted for and public questions voted upon by the electors of a municipality or of any portion thereof.