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 infection agent lacks RNA? 
Select and explain. 
A. Virus, B. Staphylococci, C. Prions, D. Cryptococcus
C: Prions
Answer: C: Prions 
Explanation: Ans. c. Prions