Correct Answer - A::B::C::D
`SO_2` can act as an oxidising agent.
`SO_2+2H_2S to 2H_2O+3S`
`SO_2` can act as a reducing agent
`SO_2+NO_2 to SO_3+NO`
`SO_2` act as a bleaching agent.
`SO_2+2H_2O to H_2SO_4 +2[H]`
The nascent hydrogen combines with the colouring matter and makes it colourless.
`SO_2` is a powerful disinfectant.
