(a) Unless the articles of incorporation or a bylaw approved by the shareholders provides otherwise, if a vacancy occurs on a board of directors, including a vacancy resulting from an increase in the number of directors:

(1) The shareholders may fill the vacancy;

(2) The board of directors may fill the vacancy; or

(3) If the directors remaining in office constitute fewer than a quorum of the board, they may fill the vacancy by the affirmative vote of a majority of all the directors remaining in office.

(b) If the vacant office was held by a director elected by a voting group of shareholders, only the holders of shares of that voting group or the remaining directors elected by that voting group are entitled to vote to fill the vacancy.

(c) A vacancy that will occur at a specific later date (by reason of a resignation effective at a later date under subsection (b) of Code Section 14-2-807 or otherwise) may be filled before the vacancy occurs but the new director may not take office until the vacancy occurs.