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
When a drug binds to the receptor and causes action opposite to that of agonist this is called as ? 
Select and explain. 
A. Complete Agonist, B. Partial Agonist, C. Inverse agonist, D. Neutral antagonist
C: Inverse agonist
Answer: C: Inverse agonist 
Explanation: None