4D. The term of office of a chairperson shall cease on the date that is the earliest to occur of the following:

(a) the date of the expiry of his or her term of office as chairperson;

(b) the date of his or her resignation or removal from office as a Commissioner;

(c) the date of his or her resignation or removal from office as chairperson;

(d) the date of he or she ceasing to hold office as a Commissioner in accordance with section 18.]