This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
What is mirabegron? 
Select and explain. 
A. Alpha 2 agonist, B. Beta 3 agonist, C. Beta 1 agonist, D. Beta 2 agonist
B: Beta 3 agonist
Answer: B: Beta 3 agonist 
Explanation: Mirabegron used in overactive bladder which is a selective b3 agonist.