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
Nasopharyngeal Ca is caused by - 
Select and explain. 
A. EBV, B. papillomavirus, C. papillomavirus, D. Adenovirus
A: EBV
Answer: A: EBV 
Explanation: Epstein- Barr virus is closely associated with nasopharyngeal cancer. Specific viral markers are being developed to screen people in high incidence areas.