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: Tα CD4 + lymphocytes: 
 Options:  <1> They are functionally cooperative with B lymphocytes and other T lymphocytes. <2> They recognize native antigens in soluble form. <3> They recognize peptides in the MHC class I context. <4> They are less abundant than CD8 + in human blood. <5> They release perforins.
