This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nose and paranasal sinuses, Subject name: ENT
[{'content': 'Basal skull view X-ray is best to visualize \nSelect and explain. \nA. Ethmoid sinus, B. Frontal sinus, C. Sphenoid sinus, D. Maxillary sinus', 'role': 'user'}, {'content': 'Answer: C \nExplanation: submento veical view This view is taken with veex near the film and x-ray beam projected at right angles to the film from submental area. Structures seen are External auditory canal Middle ear cleft i.e. mastoid air cells, middle ear and eustachian tube Internal auditory canal Sphenoid sinus Foramen ovale Carotid canal (Ref: Textbook of diseases of ENT, PL Dhingra, 7th edition, pg no. 493)', 'role': 'assistant'}]