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
Silver impregnation method of staining is useful to demonstrate 
Select and explain. 
A. Bacterial flagella, B. Spirochetes, C. Both of the above, D. None of the above
C: Both of the above
Answer: C: Both of the above 
Explanation: None