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: Which of the following chemicals is considered the most lethal individual carcinogen? 
 Options:  <1> Alcohol. <2> Smoke of the tabacco. <3> Tar. <4> Benzene. <5> Nickel.
