Explain how the following modifications to cell structure could increase efficiency of materials exchange between the cell and its environment: the cell is thin and flat the cell has extensions such as cilia on its membrane the cell uses vesicles to move materials.

All the options are going to reduce the time to get in or get out materials from the cell.

Explanation:

If the cell is thin and flat, the membrane will be thinner also, hat means that the particles that want to get in, could enter easily because the lipid layer is not so thick.

If the cell has extensions such as cilia, it will increase the membrane area, the contact area, that means that it will increase the possibility for a substance to get inside, for example, if a molecule can easily get in, if there are a bigger area, more molecules can enter to the cell.

If the cell uses vesicles to move materials, also will increase the probability to carry substances inside the cell because there are  more "buses" to carry "passengers" inside.

i believe the correct answer is d

i would say it is