Compare 2 shapes. Which would be more efficient if nutrients were being exchanged through them?

This is a question of the ration surface-volume. It is more efficient a shape that has more surface than volume

Explanation:

Imagine the shape of a mouse and an elephant in a cold environment. Who will lose heat faster? The answer is the mouse, for its volume (which is small compared to the elephant), the surface for which it can lose heat is very large. In contrast, the surface for which the elephant can lose heat is very small for its volume.

The same happens with nutrients if you have a great volume and a small surface is more difficult to exchange them.