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
Prions consists of - 
Select and explain. 
A. DNA and RNA, B. DNA, RNA and Protein, C. RNA and protein, D. Only proteins
D: Only proteins
Answer: D: Only proteins 
Explanation: Ans. is 'd' i.e., Only proteins