Definition: In this task, you are given a multiple-choice question about healthcare. Answer the question based on your information and classify your answers into '1', '2', '3', and '4'.
Input: Question: Which of the nucleophiles listed below has a greater reactivity to the bimolecular nucleophilic substitution reaction? 
 Options:  <1> Hydroxide. <2> I last. <3> Ammonia. <4> Water. <5> Acetic acid.
