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: What type of receptor is responsible for activating most of the responses to the hormone T3 ?: 
 Options:  <1> A protein G. <2> An ABC protein. <3> A nuclear receiver. <4> A receiver coupled to an ion channel. <5> A plasma membrane glycoprotein.
