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
Entacapone is an anti–Parkinsonism drug. It acts by : 
Select and explain. 
A. Agonism at dopamine receptors, B. Antagonism at dopamine receptors, C. Monoamine oxidase inhibition, D. Cathecol–o–methyl transferase inhibition.
D: Cathecol–o–methyl transferase inhibition.
Answer: D: Cathecol–o–methyl transferase inhibition. 
Explanation: None