This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Virology, Subject name: Microbiology
MgCl2 is added to polio vaccine because of the following - 
Select and explain. 
A. Potentiates the vaccine, B. Vaccine can be kept at higher temperatures, C. Preservative, D. None of the above
B: Vaccine can be kept at higher temperatures
Answer: B: Vaccine can be kept at higher temperatures 
Explanation: molar MgCl2 is used to dtabilise the vaccine against heat inactivation REF:ANATHANARAYANAN MICROBIOLOGY NINTH EDITION PAGE.488