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: Gynaecology & Obstetrics
[{'content': 'Regarding diagnostic tests for syphilis, true is all except \nSelect and explain. \nA. VDRL test is used for measurement of antibody titers to assess response to treatment., B. FTA-ABS is used to confirm diagnosis in clinically suspected syphilis., C. TP-PA test is appropriate for population screening for syphilis., D. Fourfold decrease in titer is required by 6 months after therapy for primary syphilis.', 'role': 'user'}, {'content': 'Answer: C \nExplanation: For population screening for syphilis, VDRL or RPR test is appropriate.', 'role': 'assistant'}]