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': 'Following is the cause for sudden loss of vision in diabetic patient: \nSelect and explain. \nA. Central material aery block, B. Vitreous haemorrhage, C. Tractional retinal detachment, D. Neovascular glaucoma', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Vitreous haemorrhage', 'role': 'assistant'}]