Task: Question Answering
Input (English): Question: Allopurinol, as an inhibitor of xanthine oxidase: 
 Options:  <1> It is suicidal, reversible. <2> It is suicidal, irreversible. <3> It is analogous to the transition state, reversible. <4> Inhibits the enzyme by proteolysis. <5> Allopurinol does not inhibit that enzyme.
Output (English): 2