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: Radiology
[{'content': 'A 50 year old male patient complains of reduced mouth opening. Patient gives h/o RTA 1 week back. Submentovertex view x-ray was taken which revealed zygomatic arch fracture. Which of the following is true regarding the central beam in this x-ray- \nSelect and explain. \nA. It is parallel to the image receptor, B. It is directed from skull to the mandible, C. It is centered about 2 cm anterior to a line connecting the right and left condyles, D. It is posterior to a line connecting the right and left coronoid process', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Submentovertex view-\nThe central beam is perpendicular to the image receptor, directed\xa0from below the mandible toward the vertex of the skull (hence the\xa0name submentovertex), and centered about 2 cm anterior to a line\xa0\nconnecting the right and left condyles.\nWhite and Pharoah, Oral radiology, ed 7th, pg-161', 'role': 'assistant'}]