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: The MIC-A protein, expressed in various cell types and induced by cellular stress situations, is recognized by: 
 Options:  <1> KIR receivers. <2> The Major Histocompatibility Complex (MHC). <3> The NKG2D receptor. <4> B lymphocytes <5> NOD type receivers.
