The interaction between \(\pi\) bond and lone pair of electrons present on an adjacent atom is responsible for [JEE Main…

Correct Option: A – Resonance effect

The resonance effect arises when there is a π bond (double bond) and a lone pair of electrons on an adjacent atom. This allows delocalization of electrons through overlapping p-orbitals, creating multiple contributing structures (resonating structures) for a molecule.

In phenol, the lone pair on oxygen interacts with the π electrons of the benzene ring, resulting in resonance.

So, the interaction between a π bond and a lone pair on an adjacent atom is characteristic of the resonance effect.