(a) A board of directors must consist of one or more natural persons, with the number specified in or fixed in accordance with the articles or bylaws.

(b) The articles or bylaws may authorize the members of the board of directors to fix or change the number of directors or may establish a variable range for the size of the board of directors by fixing a minimum and maximum number of directors. If the variable range is established, the number of directors may be fixed or changed from time to time, within the minimum and maximum, by the members, or if the articles or bylaws so provide, by the board of directors.