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: About free radicals: 
 Options:  <0> They are compounds that contain two or three unpaired electrons in an outer orbital. <1> Reactive oxygen species (ROS) in the cell are only generated enzymatically. <2> Hydrogen peroxide is the most damaging radical in the cell. <3> The hydroxyl radical originates non-enzymatically (Heber-Weiss reaction) and damages proteins and DNA. <4> Oxygen is a triradical.
chemistry

Question: The virions of the Arenavirus contain: 
 Options:  <0> A linear single-stranded RNA molecule. <1> Two equal molecules of linear double-stranded RNA. <2> Two different molecules of linear single-stranded RNA. <3> Two distinct molecules of single-stranded circular RNA. <4> Two identical molecules of single-stranded circular RNA.
biology

Question: When screening for a disease, aimed at high-risk groups, looking for disease in its initial stage, is called: 
 Options:  <0> Simple screening, non-selective, precocious. <1> Simple, selective, precocious screening. <2> Multiple, non-selective, late screening. <3> Multiple screening, selective, precocious. <4> Simple, selective, delayed screening.

medicine