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 young patient present with significant loss of central vision and a normal ERG. There is no obvious family history of similar presentation. The most likely diagnosis - \nSelect and explain. \nA. Best's disease, B. Stargardt's disease, C. Retinitis Pigmentosa, D. Cone Rod Dystrophy", 'role': 'user'}, {'content': "Answer: B \nExplanation: Loss of central vision along with a normal ERG is consistant with a diagnosis of Best's disease and stargardt's disease. Absence of a positive family history favours a diagnosis of stargardt's disease.\nStargardt's disease being an autosomal recessive disorder may not reveal a positive family history. Best's disease, being an autosomal dominant disorder should have a positive family history.", 'role': 'assistant'}]