The correct option is C Alternate director
If so authorized by the Articles or by a resolution passed by the company in general meeting, the Board may appoint an Alternate Director to act for a Original Director, who is absent for whatever reason for a minimum period of three months from the State in which the meetings of the Board are ordinarily held. Such Alternate Director will hold office until such period that the Original Director would have held his or her office. However, any provision for automatic re-appointment of retiring Directors applies to the Original Director and not to the Alternate Director.