This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: general microbiology, Subject name: Microbiology
Vaccines are sterilized by? 
Select and explain. 
A. Seitz filtration, B. Hot air oven, C. Autoclaving, D. Heat inactivation
D: Heat inactivation
Answer: D: Heat inactivation 
Explanation: Vaccines may be prepared by heat inactivation of bacteria. Thus heat can be employed to free the vaccine from other contaminants. REF:Textbook of microbiology Ananthanarayan, and Paniker.