In the event of a vacancy or the temporary absence or disability of the head of any administrative department or division authorized by or created pursuant to this Charter, (A) the Mayor may appoint an acting Chief of Police for the Police Department until the vacancy is filled or the temporary absence or disability is removed, and (B) the Administrator, for every other department besides the Police Department, may appoint an acting head of the department or division until the vacancy is filled or the temporary absence or disability is removed.