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': "Retinitis Pigmentosa is associated with all except: \nSelect and explain. \nA. Usher Syndrome, B. Marfan's Syndrome, C. Kearns- Sayre Syndrome, D. Bassen - Kornzweig Syndrome", 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. Marfan syndrome', 'role': 'assistant'}]