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 second generation 3 blocker? 
Select and explain. 
A. Propronolol, B. Timolol, C. Nodalol, D. Atenolol
D: Atenolol
Answer: D: Atenolol 
Explanation: Ans. is 'd' i.e., Atenolol