Which of the following is an impoant disinfectant on account of effectively destroying gram positive and gram negative bacteria, viruses and even spores at low pH levels?

Chlorine is used commonly as hypochlorites chlorine and hypochlorite are markedly bactericidal. They have a wide spectrum of action against viruses. The organic chloramines are used as antiseptics for dressing wounds REF:Ananthanarayan & Panicker's Textbook of Microbiology 9th edition pg no:35