Alan observed that a lot of soil from his garden swept off from after heavy rain. Which is this process called? A. groundwater recharge B. snow melt C. infiltration D. surface runoff

I'd say infiltration

Infiltration Definition-When precipitation hits the ground, it has two options depending on where it is in its story line. It may infiltrate the soil or continue across the land as runoff. Infiltration occurs when surface water enters the soil. This process is similar to pouring water onto a sponge.

Your answer is D, surface runoff.