Task: Text Categorization
Input (English): Question: What pair of modified amino acids is very common in collagen? 
 Options:  <0> 4-Hydroxy-proline and 5-Hydroxy-lysine. <1> Histamine and 5-Methyl-lysine. <2> Carboxyglutamate and 4-Hydroxy-proline. <3> S-Adenosyl-methionine and 5-Methyl-proline. <4> Methyl-Phenylalanine and Histamine.
Output (English): chemistry