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
Buprenorphine acts by following mechanism 
Select and explain. 
A. Mu receptor antagonist, B. Kappa receptor antagonist, C. Mu receptor partial agonist, D. Kappa receptor partial agonist
C: Mu receptor partial agonist
Answer: C: Mu receptor partial agonist 
Explanation: None