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
Bone morphogenic protein receptor 2 gene abnormality seen in 
Select and explain. 
A. Interstitial lung disease, B. Pulmonary aery hypeension, C. cystic fibrosis, D. Diaphragmatic weakness
B: Pulmonary aery hypeension
Answer: B: Pulmonary aery hypeension 
Explanation: primary pulmonary hypeension is idiopathic (BMPR gene abnormality).