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: In comparison with polyclonal antibodies, a monoclonal antibody: 
 Options:  <1> It has low cost. <2> It has heterogeneous specificity. <3> It is of variable specificity. <4> Recognizes a single epitope. <5> It is of variable affinity.
