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
Weil Felix test is useful in diagnosis of the following except- 
Select and explain. 
A. Epidemic typhus, B. Scrub typhus, C. RMSF, D. Trench fever
D: Trench fever
Answer: D: Trench fever 
Explanation: Ans. is 'd' i.e., Trench fever . Weil Felix reaction is not diagnostic for Q fever, Rickettsial pox and Trench fever.