Task: Text Categorization
Input (English): Question: Which of the following antitumor agents acts forming a covalent and irreversible complex with the thymidylate synthase and its cofactor, previous activation to the corresponding deoxynucleotide? 
 Options:  <0> Methotrexate <1> Bortezomib. <2> Cyclophosphamide <3> 5-Fluorouracil. <4> Taxol.
Output (English): pharmacology