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: The hepatic synthesis of methionine from homocysteine ​​requires: 
 Options:  <0> N5, N10 methenyl-tetrahydrofolate. <1> N10-formyl-tetrahydrofolate. <2> N5-formimino-tetrahydrofolate. <3> N5-methyl-tetrahydrofolate. <4> N5, N10 methylene-tetrahydrofolate.
[A]: chemistry


[Q]: Question: The reactivity of various carbonyl groups is determined by their relative stability. The order of reactivity towards nucleophiles is: 
 Options:  <0> Amides> Esters> Ketones> Aldehydes. <1> Aldehydes> Ketones> Esters> Amides. <2> Amides> Ketones> Aldehydes> Esters. <3> Aldehydes> Esters> Ketones> Amides. <4> Amides> Ketones> Esters> Aldehydes.
[A]: chemistry


[Q]: Question: In the titration curve of a diprotic acid, the three points whose pH only depends on the dissociation constants are: 
 Options:  <0> The starting point and the equivalence points. <1> The first point of equivalence and the two points of semi-neutralization. <2> The first semi-neutralization point and the two equivalence points. <3> The starting point, the first semi-neutralization point and the first equivalence point. <4> The starting point and the two semi-neutralization points.
[A]:
chemistry