Task: Text Categorization
Input (English): Question: Atenolol is an antihypertensive β-antagonist that belongs to the structural family: 
 Options:  <0> Arylethanolamines <1> Quinazolines <2> β-Haloalkylamines. <3> Aryloxypropanolamines. <4> 2-Imidazolines.
Output (English): pharmacology