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: ENT
[{'content': 'Nasopharyngeal Ca is caused by - \nSelect and explain. \nA. EBV, B. papillomavirus, C. papillomavirus, D. Adenovirus', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Epstein- Barr virus is closely associated with nasopharyngeal cancer. Specific viral markers are being developed to screen people in high incidence areas.', 'role': 'assistant'}]