Task: Text Categorization
Input (English): Question: The ribonucleotide reductase: 
 Options:  <0> Involved in the synthesis of deoxyribonucleotides. <1> It uses NADPH as a coenzyme. <2> It is an enzymatic system. <3> Acts in collaboration with the thioredoxin. <4> All the above is true.
Output (English): chemistry