Task: Text Categorization
Input (English): Question: Topoisomerases: 
 Options:  <0> They modify the degree of DNA supercoiling. <1> They are a type of DNA polymerases. <2> They bind to the single-stranded DNA to prevent the double helix from forming. <3> They exhibit exonuclease activity. <4> They synthesize dNTPs.
Output (English): biology