Given the task definition and input, reply with output. In this task, you are given a question and answer options for that question. Using this information, you have to classify each text into different topics: medicine, nursery, psychology, chemistry, pharmacology, biology.

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.
chemistry