Task: Question Answering
Input (English): Question: Indinavir is a selective inhibitor of HIV protease because: 
 Options:  <1> By hydrolysis, the active drug is generated. <2> Rents irreversibly the active center of the enzyme. <3> Its structure mimics the transition state of the reaction catalyzed by the enzyme. <4> It is a suicide inhibitor. <5> Its symmetric structure interacts effectively with the active center of the enzyme.
Output (English): 3