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: Ophthalmology
[{'content': 'Most common complication of extracapsular cataract surgery is: \nSelect and explain. \nA. Retinal detachment, B. Opacification of posterior capsule, C. Vitreous haemorrhage, D. Bullous keratopathy', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. Opacification of posterior capsule', 'role': 'assistant'}]