instruction:
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:
Question: Fibrinogen is activated by: 
 Options:  <0> Platelet stopper <1> Plasmina. <2> Thrombin <3> Thromboplastin. <4> Factor von Willebrand.
answer:
biology


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: 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