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
Which of the following provides best guarantee for sterilization in the heat sterilizer? 
Select and explain. 
A. Using chemical indicator strip or pouch, B. Recording a temperature/pressure readings from sterilizer gauge, C. Using a bacterial spore test, D. Determining the ability of a sterilizer to kill the hepatitis B virus
C: Using a bacterial spore test
Answer: C: Using a bacterial spore test 
Explanation: None