This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Pharmacology
[{'content': 'All are used for the treatment of pulmonary hypeension EXCEPT: \nSelect and explain. \nA. Endothelin receptor antagonists, B. Phosphodiesterase inhibitors, C. Calcium channel blockers, D. Beta blockers', 'role': 'user'}, {'content': 'Answer: D \nExplanation: CCBs, ET antagonists are used in Pul.HTN apa from PGI2 analogues and PDE5 inhibitors No- nitric oxide - only therapeutic use is Pul. HTN in newborn betablockers- no role Ref: KD tripathi 8th ed.', 'role': 'assistant'}]