Which of the following statements is incorrect.

Hydrogen bond does not play role in the boiling point of HI, HBr and HCl

All halogens(VIIA group elements) exhibit variable valency

Halogens either gain an electron by forming ionic bond or form a covalent bond by sharing an electron

The reducing power of halide ions is  ${\mathrm{I}}^{-}>{\mathrm{Br}}^{-}>{\mathrm{Cl}}^{-}$