Task: Question Answering
Input (English): Question: (-) - Deprenyl (or selegiline) is a propargylamine that is used in the treatment of Parkinson's disease because it is: 
 Options:  <1> Dopamine D2 receptor agonist. <2> Dopamine antagonist. <3> COMT inhibitor. <4> Dopamine prodrug. <5> Suicide inhibitor of the MAO-B.
Output (English): 5