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.
Q: Question: The structures of the condensed chromosomes are maintained by: 
 Options:  <0> Topoisomerases <1> Nucleolus proteins. <2> Fragments of Okazaki. <3> SMC proteins. <4> DNMT1 protein.
A:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
pharmacology