This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology, Subject name: Microbiology
[{'content': 'MgCl2 is added to polio-vaccine because of the following \nSelect and explain. \nA. Potentiates the vaccine, B. Vaccine can be kept in higher temperature, C. Preservative, D. None', 'role': 'user'}, {'content': 'Answer: B \nExplanation: (Vaccine can be kept in higher temperature) (491- A7th)* Molar MgCl2 protects the virus against heat inactivation* Poliovirus is resistant to ether, chloroform, bile protelytic enzymes of the intestinal contents and detergents* It is stable at PH-3* It is readily inactivated by heat (55degC for 30 minutes)* Chlorination destroys the virus in water, but organic matter delays inactivation* Phenolic disinfectants are not effective* Poliovirus does not survive lyophisation well', 'role': 'assistant'}]