This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous (Infection), Subject name: Surgery
Which is not an investigation of syphillis : 
Select and explain. 
A. VDRL, B. FTA-ABS, C. Weil-Felix, D. TPI
C: Weil-Felix
Answer: C: Weil-Felix 
Explanation: Ans is 'c' ie Weil-FelixWeil-Felix is not an inv. for Syphilis.