Task: Text Categorization
Input (English): Question: In the aromatic electrophilic substitution with a monosubstituted benzene ring, the halogens are: 
 Options:  <0> Ortho / for leaders but activating. <1> Target leaders but activating. <2> Goal / for leaders but activating. <3> Ortho / goal leaders but activating. <4> Ortho / for leaders but deactivators.
Output (English): chemistry