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
A darkfield microscope would be useful in examining blood for: 
Select and explain. 
A. Treponema, B. Actinomyces, C. Streptococcus, D. Mycobacterium
A: Treponema
Answer: A: Treponema 
Explanation: None