Question

In many plants, stomata are found only on the lower surface of the leaf. The most likely explanation for this fact is that

A. photosynthesis only occurs in the spongy mesophyll near the bottom of the leaf.

B. stomata are closer to vascular bundles that bring water into the leaf.

C. gravity plays a role in gas exchange.

D. water loss would be less on the shaded lower surface than in direct sun.