Detailed Instructions: 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'.
Problem:Question: What is the first level of organization of DNA in chromosomes':
Options: <1> Histones. <2> Nucleosomes. <3> Sugar-phosphate chains. <4> Proteosomes <5> Nucleotides
Solution:
2