D.) Is the most sensible answer.
Explanation: I used the process of elimination to solve this. Groundwater recharge sounds too far off of the topic, snow melt is...well...melting snow, infiltration also has nothing to do with the subject, but surface runoff is the only one that makes sense, is on topic, and seems to have a meaning similar to the occurrences describes in your question.
Smaller molecules diffuse easily as compared to the larger molecules. In other words, smaller is the size of molecule, easier and faster is its diffusion across a semipermeable membrane.
Hope I helped
Answer: Food
Explanation: Organisms get the energy they need through food. Some organisms, called autotrophs, create their own food using photosynthesis.
