How does imidacloprid kill foliage feeding insects?

Imidacloprid is a systemic insecticide, which means it can be absorbed by plants and then transported through their tissues. When applied to the soil or foliage, imidacloprid moves into the plant and makes its way to the leaves, where foliage-feeding insects might consume it. This ability to penetrate plant tissues and move throughout the plant is what makes option B the correct answer.

The other methods mentioned do not accurately describe the mechanism of action for imidacloprid. While contact poisoning is a method for some insecticides, imidacloprid primarily works systemically. Rapid dehydration is not a mechanism specific to imidacloprid; instead, it might be more relevant for other insecticidal products that cause desiccation. Finally, blocking photosynthesis does not pertain to how imidacloprid functions, as it targets the nervous system of insects rather than affecting the plant's photosynthetic processes.