This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Medicine
[{'content': 'Bone morphogenic protein receptor 2 gene abnormality seen in \nSelect and explain. \nA. Interstitial lung disease, B. Pulmonary aery hypeension, C. cystic fibrosis, D. Diaphragmatic weakness', 'role': 'user'}, {'content': 'Answer: B \nExplanation: primary pulmonary hypeension is idiopathic (BMPR gene abnormality).', 'role': 'assistant'}]