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: In the translation of prokaryotes, the first tRNA:
Options: <1> It is introduced in site A. <2> Join a methylated amino acid. <3> It is accompanied by the IF2 factor. <4> It is paired with a UGA start codon. <5> Always join serina.
Output:
3