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
After giving treatment for syphilis ,the response to treatment can be best assessed by? 
Select and explain. 
A. FTA-ABS, B. VDRL, C. TPHA, D. Immobilisation
B: VDRL
Answer: B: VDRL 
Explanation: None