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
All are used for the treatment of pulmonary hypeension EXCEPT: 
Select and explain. 
A. Endothelin receptor antagonists, B. Phosphodiesterase inhibitors, C. Calcium channel blockers, D. Beta blockers
D: Beta blockers
Answer: D: Beta blockers 
Explanation: 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.