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: Medicine
[{'content': 'Ataxia telangiectasia is chracterised by all of the following except: \nSelect and explain. \nA. Chronic sinopulmonary disease, B. Decreased level of a-fetoprotein, C. Chromosomal breakage, D. IgA deficiency', 'role': 'user'}, {'content': "Answer: B \nExplanation: Increased levels of a fetoproteins is seen in ataxia telangiectasia. Ref: Harrison's Principles of Internal Medicine, 17th Edition O P Ghai Essential Pediatrics, 6th Edition", 'role': 'assistant'}]