sulphur dioxide act as bleaching agent in moist conditions because of reducing nature of SO₂

SO₂ + 2H₂O H₂SO₄ + 2H

COLOURED SUBSTANCE + H = COLOURLESS SUBSTANCE

Its dilute solution is also used as disinfectant.

It does not have linear shape. It has trigonal planar geometry and bent shape.

Hence the correct options are (i)and(iii)