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: Ribosomes have three binding sites for the transfer RNAs (RNAs), which are: 
 Options:  <0> Site A of acetyl, P of propyl and E of ethyl. <1> A site of aminoacyl, P of peptidyl and E of exit (from English, exit). <2> A site of aminoacyl, peptidyl P and transferase T of the peptide. <3> Site A of previous, P of posterior and E of entry (of English, entry). <4> A site of aminoacyl, peptidyl P and terminating T.
answer:
pharmacology


question:
Question: Among other properties with respect to hypericin we can indicate: 
 Options:  <0> It is a powerful hepatoprotector extracted from the roots of Hypericum perforatum. <1> It is a powerful cholagogue that is extracted from the resin of the Hypericum perforatum rhizome. <2> It is a removable antiretroviral of the aerial parts of Hypericum perforatum. <3> It is a laxative that is extracted from the leaves of Hypericum perforatum. <4> It is a potent hepatoprotective present in the fruits of Hypericum perforatum.
answer:
pharmacology


question:
Question: The great diversity of immunoglobulins is mainly due to the recombination of: 
 Options:  <0> Epitopes. <1> Light chains <2> Heavy chains <3> Exons <4> Introns
answer:

chemistry