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: 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%
A:
pharmacology