This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Central Nervous system, Subject name: Pharmacology
Which of the following agents enhances the bioavailability of levodopa in patients with Parkinson's disease: 
Select and explain. 
A. Amantadine, B. Ropinirole, C. Entacapone, D. Selegiline
C: Entacapone
Answer: C: Entacapone 
Explanation: Entacapone & tolacapone which cones under COMT INHIBITORS enhance & prolong the therapeutic effect of levodopa-carbidopa in advanced & fluctuating PD . Ref: KD Tripathi 8th ed.