The question asks: Which of the following compounds is non-aromatic?

However, the actual structures/options A, B, C, and D are missing in the prompt. Since aromaticity depends entirely on the structure, we must know the compound in each option to decide whether it is:

1. Aromatic – cyclic, planar, fully conjugated, and follows Hückel's rule $(4n+2)pi$ electrons.
2. Anti-aromatic – cyclic, planar, fully conjugated, but has $4n$ pi electrons.
3. Non-aromatic – fails one or more of the requirements: not planar, not fully conjugated, or not cyclic.

Step-by-step aromaticity test

For any option, we would check:

1. Is the molecule cyclic?
2. Is it planar (or capable of planarity)?
3. Does it have continuous overlap of p-orbitals (fully conjugated)?
4. How many pi electrons are present?
   • If $(4n+2)$, it is aromatic.
   • If $4n$, it is anti-aromatic (if planar and conjugated).
   • If conjugation/planarity is broken, it is non-aromatic.

Problem here

Because none of the structures are shown, it is impossible to independently derive whether option D is truly non-aromatic.

So, based only on the visible information:

• I cannot verify the answer rigorously.
• The stored answer is D, but there is no structural data to confirm it.

Conclusion

With the options missing, the question is incomplete. A correct solution requires the structures of A, B, C, and D.