Which of the following statement is not true for benzene?

It contains three localized pi bonds

Localized vs. Delocalized π Bonds (Option d):
In benzene, the π electrons are delocalized, forming a continuous π electron cloud above and below the ring. This delocalization is what gives benzene its stability and unique properties. The statement that benzene has "three localized π bonds" is incorrect, as the π electrons are not confined to specific bonds but spread out over the entire ring.

Why other options are true:

Planarity of Benzene (Option a):
Benzene is a planar molecule, meaning all its atoms lie in the same flat plane. This is because the six carbon atoms form a ring with sp² hybridized orbitals, giving it a flat, hexagonal structure.

Equal Bond Lengths (Option b):
All the C-C bond lengths in benzene are equal, measured as 1.39 Å. This happens because of resonance—the electrons in the π bonds are delocalized over the entire ring, creating a uniform bond length instead of alternating single and double bonds.

Resonance Energy (Option c):
Benzene is stabilized by resonance, with a resonance energy of 36 kcal/mole. This energy makes benzene much more stable than what is expected for a structure with three localized double bonds.