The electrophile and intermediate formed in the Reimer – Tiemann reaction are

The Reimer–Tiemann reaction is a classic reaction used to form ortho-formyl derivatives of phenols (like salicylaldehyde from phenol).

Electrophile formed:

In this reaction, chloroform (CHCl₃) reacts with a strong base (like NaOH) to form the highly reactive dichlorocarbene (:CCl₂).

This :CCl₂ is the electrophile that attacks the phenol.

Intermediate formed:

When the phenoxide ion (from phenol + base) reacts with the electrophile (:CCl₂), it forms an intermediate called dichloromethyl phenol (or a resonance-stabilized phenoxide-carbene complex).

This intermediate then undergoes hydrolysis under basic conditions to give the ortho-formyl phenol (final product).

So, in simple terms:

Electrophile: Dichlorocarbene (:CCl₂)

Intermediate: Dichloromethyl phenoxide (before hydrolysis)

This matches option B, because B correctly identifies the reactive carbene electrophile and the intermediate formed during the reaction.