Given are cyclohexanol (I), acetic acid (II), 2, 4, 6-trinitrophenol (III) and phenol (IV). In these the order of decreasing acidic character will be
III > IV > II > I
III > II > IV > I
II > III > I > IV
II > III > IV > I
in(iii), there are three groups which have both - I and -M effect hence it is most stabilized after donating H+.
Because of resonance it is more stable.
Due to resonance this is stable.
SO, order will be
III > II > IV > I.