This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Sexually Transmitted Infections, Subject name: Dental
25 yrs old labourer 3 yrs back presented with penile ulcer which was not treated. Later he presented with neurological symptoms for which he got treated. Test to monitor response to treatment is- 
Select and explain. 
A. VDRL, B. FTA ABS, C. TPI, D. RPR
A: VDRL
Answer: A: VDRL 
Explanation: Labourer is suffering from neurosyphilis. Best test to monitor response to treatment is VDRL- CSF, Blood Titer of > 1:8 is +ve and titre of <1:8 is a False +ve VDRL.