Task: Text Categorization
Input (English): Question: A compound that has a five-membered aromatic heterocyclic skeleton with three carbon atoms and two nitrogens, the latter being positions 1 and 3, is called: 
 Options:  <0> Pirrol. <1> Pyrimidine <2> Pyrazole <3> Pyrazolidine. <4> Imidazole
Output (English): chemistry