Task: Text Categorization
Input (English): Question: Sulfasalazine is used for the treatment of ulcerative colitis. It is a prodrug of 5-aminosalicylic acid that is activated by a process of: 
 Options:  <0> Hydrolysis of an ester. <1> Hydrolysis of an amide. <2> Oxidative dealkylation. <3> Reducing rupture of the azoderivative. <4> Aromatic hydroxylation.
Output (English): pharmacology