Biology

The correct answer is: A.The concentration gradient

The main driving force behind the diffusion of gases such as oxygen and carbon dioxide is the concentration gradient. Gases naturally move from areas of higher concentration to areas of lower concentration, which is known as simple diffusion. This movement continues until equilibrium is reached, where the concentration of the gas is the same on both sides of the membrane.

In contrast:

B.The temperature gradient can influence the rate of di...