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
All are used for treating Pulmonary hypertension 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: None