The officers of a cooperative are those officers authorized by the bylaws. The officers shall be elected annually by the board of directors from among its members. If authorized by the bylaws, the election may be conducted by written ballot. When a person holding an office ceases to be a director, that person ceases to hold office. The board of directors may appoint those other agents or employees that it considers necessary or advisable and shall prescribe their powers and duties. An officer may be removed from office and a successor elected in the manner prescribed in the bylaws.