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: What simple reinforcement programs produce a more stable response pattern ?: 
 Options:  <0> Those of fixed ratio. <1> Those of variable reason. <2> Those of fixed interval. <3> Those of variable interval. <4> All reinforcement programs produce similar response rates.
answer:
psychology


question:
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.
answer:
chemistry


question:
Question: A study is carried out to investigate the association between factor X and disease Z. To do this, 120 subjects with the disease and 420 controls (without the disease) are matched by age and sex. In both groups it is found that 20 subjects were exposed to factor X. What is the odds ratio (OR) between factor X and disease Z? 
 Options:  <0> OR = 1 (no association). <1> OR = 2. <2> OR = 4 <3> OR = 6 <4> OR = 8
answer:

medicine