This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
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 - 
Select and explain. 
A. Phenol, B. Alcohol, C. Chlorine, D. Hexachlorophene
C: Chlorine
Answer: C: Chlorine 
Explanation: Ans. is 'c' i.e., Chlorine