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': 'Commonest cause of vitreous haemorrhage is: \nSelect and explain. \nA. Diabetes, B. Hypeension, C. Trauma, D. Lens extraction', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. Trauma', 'role': 'assistant'}]