Chemistry - GOC Question with Solution | TestHub

Important resonance contributors must satisfy: complete octet, minimum charge separation, and proper placement of charges.

(A) is valid since both structures have complete octet and reasonable charge distribution → important.

(B) is important because charge is delocalized between electronegative atoms, increasing stability.

(C) is valid as resonance involves only electron shift (no change in atom position) → contributes.

(D) is not valid since it involves change in σ-bond framework (tautomer-like), not pure resonance.

Hence, correct answer: A, B, C