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': 'Vitreous hemorrhage produces ? \nSelect and explain. \nA. Sudden painless loss of vision, B. Sudden painful loss of vision, C. Gradual painless loss of vision, D. Gradual painful loss of vision', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Sudden painless loss of vision", 'role': 'assistant'}]