Detailed Instructions: In this task, you are given a question and answer options for that question. Using this information, you have to classify each text into different topics: medicine, nursery, psychology, chemistry, pharmacology, biology.
Problem:Question: In relation to the structure of proteins:
Options: <0> All globular proteins have the same domains. <1> The tertiary structure is present only in oligomeric proteins. <2> Hemoglobin is the only protein that has a quaternary structure. <3> The protein domains are regions of compact folding that exert a certain function. <4> The tertiary and quaternary structures are maintained only by the peptide bonds.
Solution:
biology