Arrange above phenol in increasing order of ${\mathrm{pK}}_{\mathrm{a}}$ value:

${\mathrm{K}}_{\mathrm{a}}\mathrm{order}\mathrm{in}:\mathrm{I}<\mathrm{II}<\mathrm{III};{\mathrm{pK}}_{\mathrm{a}}\mathrm{order}:\mathrm{III}<\mathrm{II}<\mathrm{I}$

Presence of   electron withdrawing group at -ortho and -para positions increases the acidic nature of phenols.