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.
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Question: 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.

Answer: chemistry


Question: Question: The gas used to generate the ICP plasma (coupled induction plasma) is: 
 Options:  <0> Hydrogen for being diatomic, chemically inert and with a low ionization energy. <1> Oxygen because it is diatomic, highly reactive and with a high ionization energy. <2> Argon, being monatomic, chemically inert and with a high ionization energy. <3> Xenon, being monatomic, highly reactive and with a low ionization energy. <4> None of the above is correct, because the gas used is helium.

Answer: chemistry


Question: Question: In relation to the process of formation of impressions, what does the phenomenon of Perceptual Defense refer to? 
 Options:  <0> Low threshold to perceive threatening stimuli. <1> Low threshold of recognition before stimuli that satisfy our needs. <2> High threshold to perceive threatening stimuli. <3> High threshold of recognition before positive stimuli. <4> Low threshold to perceive both negative and positive stimuli.

Answer:
psychology