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 of the following is a cardioselective β - blocker 
Select and explain. 
A. Timolol, B. Metaprolol, C. Carvedilol, D. Propanolol
B: Metaprolol
Answer: B: Metaprolol 
Explanation: Metaprolol is a selective β1 receptor blocker, hence cardioselective.
Note: Carvedilol is prefered in CHF cases even though its non selective β - blocker. Because it has additional anti-oxidant & anti-inflammatory property.