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: Inhibits the integrase of HIV the:
Options: <0> Efavirenz. <1> Tenofovir <2> Ritonavir <3> Emtricitabine. <4> Raltegravir
[EX A]: biology

[EX Q]: Question: Acetylsalicylic acid is a compound whose pKa is 3.5. What percentage of a dose of this product can be absorbed in the stomach fasting (pH 1.5)?
Options: <0> Less than 10% <1> Between 10% and 20%. <2> More than 90% <3> Between 20% and 40%. <4> 50%
[EX A]: pharmacology

[EX Q]: Question: To control the expression of certain genes according to population density, bacteria use systems of:
Options: <0> Strict response <1> Two components <2> Perception of the quorum. <3> Densitometric adaptation. <4> Negative activation
[EX A]:
biology