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
The biologic standard used to test the efficiency of sterilization involves the use of 
Select and explain. 
A. Spores of Clostridium tetani, B. Streptococcus pneumoniae, C. Spores of Vibrio, D. Mycoplamsa
A: Spores of Clostridium tetani
Answer: A: Spores of Clostridium tetani 
Explanation: Spores of Clostridium tetani is used for Dry Heat; 106 spores are used.For moist heat, Bacillus stearothermophilus are usedReference: Ananthanarayan and Paniker&;s Textbook of Microbiology; 10th edition