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: Reactions in which there are no intermediates are described as: 
 Options:  <0> Concerted. <1> Polar <2> Radicals <3> Homolitic <4> Heterolithic

Answer: chemistry


Question: Question: What are, among others, the main biases associated with the observer in the framework of observation techniques ?: 
 Options:  <0> The duration of the experiment. <1> The excess of information. <2> The technical accuracy <3> The illusion of learning. <4> The expectation and mechanical errors of registration.

Answer: psychology


Question: Question: Vulcanization is a chemical reaction: 
 Options:  <0> What is done in the forges. <1> Which causes crosslinking of the polymer chains. <2> That desentrecuuza the polymer chains. <3> To prepare composite materials. <4> Which leads to the development of volcanoes.

Answer:
chemistry