C. grass
is the answer because it provides food for other organisms
Answer:
It does't account for migrations or movements of nomadic animals
Explanation:
Commensalism is when a parasite feeds of of something, but doesn't hurt the host.
Green plants need water (H2O) and carbon dioxide (CO2) for the process of photosynthesis.
Although CO2 has carbon, it's inorganic (there are some chemistry rules for what compounds are organic/inorganic, but I won't talk about them here).
Both move molecules from higher concentration to lower concentration.