This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Acquired Cataract, Subject name: Ophthalmology
[{'content': 'How is posterior chamber examined in mature cataract? \nSelect and explain. \nA. Laser interferometry, B. Optical coherence tomography, C. B Scan, D. A scan', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. (c) B ScanRef: Kanski 7/e, chapter 9, Textbook of ophthalmology by H. V. nema, p 525', 'role': 'assistant'}]