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': "A 25-year-old male presents with painless sudden loss of vision. Ocular and systemic examination is not contributory. What is probable diagnosis. \nSelect and explain. \nA. Retinal detachment, B. Eale's disease, C. Glaucoma, D. Cataract", 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. Eale's disease", 'role': 'assistant'}]