The biosphere, also known as the "ecosphere", is the worldwide sum of all ecosystems (this would represented by the fish).
The hydrosphere is the combined mass of water found on, under, and above the surface of a planet earth, minor planet or natural satellite (this would be represented by the water).
The answer is D. Because planting nonnative species is bad for the area because the plants that normally grow there have to compete with that new species then.
Explanation: You're supposed to have numerically more smaller units than bigger units, since a lot of these smaller units are combined to create a single larger unit.
