The officers and employees of the city who shall be exempt from the rules and regulations of the civil service board shall include:
(a) Officers directly elected by the people;
(b) Members of advisory boards and commissions;
(c) The city manager, and any person or persons employed as assistant city manager, and confidential secretary;
(d) Those officials of the city government responsible for the operation of a city department or division, along with those persons who may be employed as assistants to such officials; and
(e) Those employees occupying positions in classes which are filled only on a part-time, seasonal, or limited term basis.
The city council shall, by resolution, designate those classes of positions, employees in which shall be considered exempt from the rules and regulations of the civil service board, in accordance with the intent and meaning of this section.