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.

[EX Q]: Question: For what purpose is the muscle tension technique applied in the treatment of blood phobia used ?: 
 Options:  <0> As a relaxation technique. <1> To divert the patient's attention from the feared stimulus. <2> To accelerate the habituation process. <3> To reduce vasovagal symptoms. <4> It is used in the first sessions to reduce anticipatory anxiety.
[EX A]: psychology

[EX Q]: Question: The proteasome: 
 Options:  <0> It is formed by 21 homologous subunits organized in 3 rings. <1> It is a protein complex that catalyzes the hydrolysis of ubiquitinated proteins. <2> It is found only in animal eukaryotic cells. <3> Digest acylated proteins. <4> It is activated by a drug, bertezomil, in therapy for multiple myeloma.
[EX A]: chemistry

[EX Q]: Question: The reaction of benzene with tertbutyl chloride, in the presence of aluminum trichloride, is an example of: 
 Options:  <0> Nucleophilic aromatic substitution reaction. <1> Electrophilic aromatic substitution. <2> Addition of halogens. <3> Acid catalyzed hydrolysis. <4> Obtaining alkyl halides.
[EX A]:
pharmacology