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. Papilloma virus, C. Parvo virus, D. Adeno virus
A: EBV
Answer: A: EBV 
Explanation: Etiology of Nasopharyngeal Carcinoma Genetic: It is most common in China. Viral: Epstein-Barr virus is closely associated with nasopharyngeal cancer. Epstein-Barr virus has identified in tumor epithelial cells (not lymphocytes) of most undifferentiated and nonkeratinizing squamous cell carcinoma. Environmental: Burning of incense or wood (polycyclic hydrocarbon); smoking of tobacco and opium; air pollution; nitrosamines from dry salted fish along with vitamin C deficient diet have been linked to the etiology of nasopharyngeal cancer.