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.

[Q]: Question: Isopropyl alcohol is prepared from petroleum by hydration of: 
 Options:  <0> Isobutene <1> Eteno <2> Penteno <3> Buteno. <4> Propene
[A]: chemistry


[Q]: Question: What kind of image appears when the individual does not fixate his attention on it and, on the contrary, disappears when he concentrates on the experience? 
 Options:  <0> Consecutive images <1> Mnemic images. <2> Hallucinoid images. <3> Abnormal images <4> Parasitic images
[A]: psychology


[Q]: Question: T-independent antigens: 
 Options:  <0> They are mostly proteins. <1> They induce maturation of the affinity of the specific antibodies. <2> Induce isotype change of specific antibodies. <3> They are usually polymeric antigens. <4> They induce intense secondary responses.
[A]:
biology