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: Which of the following situations would noticeably decrease the transcription of a gene? 
 Options:  <0> The presence of a repressor and an inducing molecule. <1> The binding of RNA polymerase to DNA. <2> The presence of a repressor and a correpressor molecule. <3> The presence of an activator and its signal molecule. <4> The presence of a mutated repressor that could not bind to DNA.
pharmacology

Question: The ketone bodies: 
 Options:  <0> They are used by the liver to synthesize fatty acids. <1> They only form in conditions of good nutrition. <2> Its formation is especially active in skeletal muscle. <3> It is formed from acetyl-CoA. <4> They never give acetone.
biology

Question: Depersonalization disorder, according to the DSM-IV-TR, is part of: 
 Options:  <0> The schizophrenic disorders. <1> Dissociative disorders <2> Somatoform disorders. <3> Disorders of the mood. <4> Personality disorders

psychology