Task: Text Categorization
Input (English): Question: The activation energy of a reaction: 
 Options:  <0> It is not modified by the action of enzymes. <1> It is the energy necessary to reach the state of transition. <2> It is lower than the energy of the substrates. <3> It is lower than the energy of the products. <4> It is an average of the value of ΔG of the reaction.
Output (English): biology