<prompt> Which of thefollowing is NOT true about nasopharyngeal carcinoma?Bimodal age distributionEBV is implicated as etiological agentSquamous cell carcinoma is commonNasopharyngectomy and lymph node dissection is mainstay of treatment  <response>: In nasopharyngeal carcinoma, radiotherapy is the mainstay of treatment. Radical neck dissection is required for persistent nodes when primary has been controlled. 