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 is the main cerebral structure involved in conditioned fear ?: 
 Options:  <1> The hippocampus <2> The cingulate cortex. <3> The olfactory bulb. <4> The hypothalamus <5> The amygdala
