Is the given molecule aromatic, antiaromatic, or nonaromatic? If it is aromatic, what is the n in Hückel's rule? If not, why does it violate the aromaticity rule?

The molecule is non-aromatic. It violates the aromaticity rule since it is not a planar, non-conjugated pi system, and n is not equal to zero or a positive integer.

The molecule is aromatic. Its n is 1.

The molecule is antiaromatic. It breaks the aromaticity rule because it does not have a (4n + 2) number of π electrons.

The molecule is antiaromatic. It violates the aromaticity rule since it is not a planar and non-conjugated pi system.