The answer is D) Structural
That is because we can automatically cross A out, and B is not the answer because ionic compounds aren't polyatomic. Poly atomic atoms are covalent and have no charge. While on the other hand, ions have a charge.
Also, C is not the answer because the molecular formula for glucose is C6H12O6, that leaves us with choice D.
I can pretty much conclude that D is the answer because you can see that the picture, it has a structure for the compound. Its showing us how the atoms are bonded and structured.