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: A potential receiver: 
 Options:  <0> It is produced by the opening of voltage-dependent channels. <1> Increase its frequency if the intensity of the stimulus increases. <2> It occurs after the binding of the neurotransmitter to the postsynaptic receptor. <3> They occur if the trigger threshold is exceeded. <4> It can be exciter or inhibitor.
[EX A]: biology

[EX Q]: 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.
[EX A]: pharmacology

[EX Q]: Question: The conception of person based on the idea that he is a being inseparably linked to his culture is developed in the care model of: 
 Options:  <0> M. E. Rogers. <1> N. J. Pender. <2> J. Watson. <3> M. Leininger. <4> M. K. Chisman and J. Riehl-Sisca.
[EX A]:
nursery