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': 'CBCT stands for \nSelect and explain. \nA. Cone beam computed tomography, B. Coil beam computed tomography, C. Combined beam computed tomography, D. Circular beam computed tomography', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Cone-beam computed tomographic (CBCT) imaging is the\xa0most\xa0significant\xa0technologic\xa0advance\xa0in\xa0maxillofacial\xa0imaging since the introduction of panoramic radiography.\xa0CBCT imaging was initially developed commercially for angiography in the early 1980s. It uses a divergent cone-shaped or pyramid-shaped\xa0 source\xa0of\xa0ionizing\xa0radiation\xa0and\xa0a\xa0two-dimensional\xa0area\xa0detector fixed on a rotating gantry to provide multiple sequential\xa0transmission images that are integrated directly, forming volumetric\xa0 information.', 'role': 'assistant'}]