Question

Which one of the following is most reactive towards electrophilic substitution reaction?

• A.
• B.
• C.
• D.

Answer 1

The correct option is B


Electron withdrawing substituent deactivates the benzene nucleus towards electrophilic substitution while electron releasing substituents activates the ring towards electrophilic substitution.
Among the given -OH has the higher $e^{-}$ donating tendency and thus activates the ring more towards electrophilic substitution. Hence, it is more reactive towards electrophilic reagents.
So option (b) is correct as it has OH attached to the benzene ring.