Answer:
The right answer to this question is option D. Convergent evolution.
Explanation:
Convergent evolution is a process defined by when an organism develops the same, or at least near that, characteristics, for a specific reason, but they don't have the same origin. In this case, the cacti in both deserts have pretty much the same characteristics, and this happens because both these plants need water to survive, and in order to save it, they have barrel-shaped stems, short-lived leaves, and spines. All of these things help them in saving the water and capturing it when it's possible.
The convergent evolution is when both these organisms develop equally, but are not originally from the same place, the environment being the one to shape this.
Simple Diffusion Across the Cell (Plasma) Membrane. The structure of the lipid bi-layer allows small, uncharged substances such as oxygen and carbon dioxide, and hydrophobic molecules such as lipids, to pass through the cell membrane, down their concentration gradient, by simple diffusion.
I believe the correct answer will be A
