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: Social & Preventive Medicine
Which if the statements is false regarding bleaching powder? 
Select and explain. 
A. 1-3% of bleach can kill most organisms, B. Contains 60% available chlorine, C. Sodium hypochlorite is a versatile disinfectant, D. Lime is used as a stabilizing agent
B: Contains 60% available chlorine
Answer: B: Contains 60% available chlorine 
Explanation: Bleaching powder contains 33% available chlorine. 1-3% kills most of the organism. Bleach, paicularly sodium hypochlorite, has been shown to react with a microbe's heat shock proteins, stimulating their role as intra-cellular chaperone and causing the bacteria to form into clumps that will eventually die off. In some cases, bleach's base acidity compromises a bacterium's lipid membrane, a reaction similar to popping a balloon. The range of micro-organisms effectively killed by bleach (paicularly sodium hypochlorite) is extensive, making it an extremely versatile disinfectant.