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
Commonest site of nasopharyngeal carcinoma is: 
Select and explain. 
A. Roof, B. Posterior, C. Lateral wall, D. Anterior wall
C: Lateral wall
Answer: C: Lateral wall 
Explanation: The lateral walls include the eustachian tube, the torus tubarius, and the fossa of Rosenmuller. The most common site of origin for nasopharyngeal carcinoma is the fossa of Rosenmuller.