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: On the link between the nitrogenous base and the ribose of the nucleotides: 
 Options:  <0> The anomeric carbon of ribose is in alpha configuration. <1> It is an N-glycosidic bond. <2> It involves the C5' of the ribose. <3> It involves phosphate groups. <4> It is of a different nature for each nitrogenous base.
[A]: biology


[Q]: Question: When comparing the characteristics of pragmatic or confirmatory clinical studies with explanatory or exploratory clinical studies, which of the following is an advantage of the former? 
 Options:  <0> Information about subgroups of patients representative of the usual clinical practice. <1> Very homogeneous sample, with little variability. <2> Greater capacity to detect differences in the effectiveness of interventions. <3> Greater internal validity <4> Smaller sample size
[A]: medicine


[Q]: Question: The molecularity of an elementary reaction corresponds: 
 Options:  <0> At the initial concentration of reagent. <1> To the number of molecules that are found to react. <2> To the number of collisions of the reactants per unit of time. <3> At the final concentration of the product. <4> To the reaction between the reaction rate and the reagent concentration.
[A]:
pharmacology