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
[{'content': 'A 10-year-old boy presents with nasal obstruction and intermittent profuse epistaxis. He has a firm pinkish mass in the nasopharynx. All of the following investigations are done in this case except- \nSelect and explain. \nA. X - ray base of skull, B. Carotid angiography, C. CT scan, D. Biopsy', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Biopsy can cause profuse bleeding, therefore should be avoided.\nInvestigations used for NFA are :-\n\n\nSoft tissue lateral film of nasopharynx\nX-ray paranasal sinus and base of skull\nContrast CT of skull (investigation of choice)\nMRI\nCarotid angiography', 'role': 'assistant'}]