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: Social & Preventive Medicine
[{'content': 'Confirmatory diagnostic test used in HIV \nSelect and explain. \nA. ELISA, B. SIMPLE test, C. Western Blot Assay, D. RAPID test', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]