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.

Question: If in an epidemiological study, the participating population has voluntariness as an inclusion criterion, the validity of the results are subject to a bias of: 
 Options:  <0> Information. <1> Confusion. <2> Selection. <3> Interpretation. <4> Publication.
nursery

Question: Atenolol is an antihypertensive β-antagonist that belongs to the structural family: 
 Options:  <0> Arylethanolamines <1> Quinazolines <2> β-Haloalkylamines. <3> Aryloxypropanolamines. <4> 2-Imidazolines.
pharmacology

Question: The DNA Girasa is: 
 Options:  <0> A eukaryotic Topoisomerase I. <1> A eukaryotic Topoisomerase II <2> A prokaryotic Topoisomerase I <3> A prokaryotic Topoisomerase II. <4> A prokaryotic Helicasa.

chemistry