What is the name of the process in which molecules move from an area of high concentration to an area of low concentration across a selectively permeable membrane?

Diffusion.

Explanation:

when molecules move from an area of high concentration (large amount) to an area of low concentration (low amount). ... In simple diffusion, molecules that are small and uncharged can freely diffuse across a cell membrane.

answer; /// i believe that the correct answer is (50%);

a. the production of carbon dioxide through the process of photosynthesis