Replacement of Cl of chlorobenzene to give phenol requires drastic conditions but chlorine of 2, 4-dinitrochlorobenzene is readily replaced. This is because
(a) NO2 makes the ring electron rich at ortho and para positions
(b) NO2 withdraws e- from meta position
(c) NO2 donates e- at meta position
(d) NO2 withdraws e- from ortho/para positions