Chlorination is a process used for water purification. The disinfecting action of chlorine is mainly due to

1. (a)The formation of hydrochloric acid when chlorine is added to water
2. (b)The formation of hypochlorous acid when chlorine is added to water
3. (c)The formation of nascent oxygen when chlorine is added to water
4. (d)The formation of hydrogen when chlorine is added to water