Inside of plants, there are xylem cells that carry water and minerals from the roots, to the leaves, when the food then gets dispersed to the rest of the plant. This is similar to the human circulatory system but there isn't a heart pumping blood around. Hope this helps :)
Answer
The answer is watershed and that is an area that catches all the rain and snow.
This is because of B. Their cells are in direct contact with the environment.