This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nasopharynx, Subject name: ENT
[{'content': 'Nasopharyngeal carcinoma does not involve: \nSelect and explain. \nA. Nasal cavity, B. Oropharynx, C. Pyriform fossa, D. Orbit', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Nasopharyngeal carcinoma does not involve the pyriform fossa. Inferiorly it may spread to the soft palate and oropharynx. Posteriorly it may spread to retropharyngeal space Laterally it may spread to the parapharyngeal space (post styloid compament). Tumors may directly invade the orbit leading to exophthalmos and blindness. Superiorly it extends intracranially by direct invasion through foramen lacerum and foramen ovale, sphenoid bone and sphenoid sinus causing multiple cranial nerve palsies.', 'role': 'assistant'}]