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: Th1 lymphocytes: 
 Options:  <1> They produce interferon gamma (IFN-γ). <2> They mediate allergic diseases. <3> Activate mast cells <4> They are very active against extracellular bacteria. <5> They recruit neutrophils at the sites of antigen recognition.
