Which of the following compound does not follow Huckel's rule?&

An aromatic compound can follow Huckel's rule if it has $( 4n + 2 ) \pi$-electrons

where, $n =$ integer $0, 1, 2, 3, \ldots$ etc.

Thus,

(a) $n = 0; 4 \times 0 + 2 = 2\pi$

$∴$ follow Huckel's rule

(b) $n = 1;$ Number of $\pi$-electrons $= 6$

$∴$ follows Huckels rules.

(c) $n = 1;$ Number of $\pi$-electrons $= 6$

$∴$ follows Huckel's rule.

(d) $n = 1$, Number of $\pi$-electrons $= 8$

$( 4n + 2 = 4 \times 1 + 2 = 6 )$

but this compound has $8$ electrons which distorts the plane and hence does not follows Huckel's rule.