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
Cold sterilization refers to the process of sterilization by use of 
Select and explain. 
A. ultra violet rays, B. Ultrasonic vibrations, C. Infrared rays, D. Gamma rays
D: Gamma rays
Answer: D: Gamma rays 
Explanation: None