I hv doubt in this question here we have to find non planar structure and option D can also be correct ?as uski hybridisation sp3d aa rhi he and vo non planar hona chahie? Experts pls tell that answer is b how and also tell why not d

Dear Student
Option (D) may appear to be no planar. But it is actually planar.
This is due to the resonance of the -ve charge with the $\mathrm{\pi }$-bond. Since the l-ve charge on C is delocalized, hence each carbon atom n the molecule is sp²-hybridized and hence planar.

Regards