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: Pharmacology
Which is beta antagonist ? 
Select and explain. 
A. Salbutamol, B. Propranolol, C. Salmeterol, D. Albuterol
B: Propranolol
Answer: B: Propranolol 
Explanation: None