Final answer:
The biosphere is a system encompassing all life and its environmental interactions on Earth, composed of the lithosphere, hydrosphere, and atmosphere.
Step-by-step explanation:
The biosphere is a system that includes all living organisms and their interactions with the nonliving components like air, land, and water on Earth.
When we look at the other parts that make up our biosphere, we refer to the lithosphere (the Earth's crust, the solid portion of the Earth), the hydrosphere (all water sources on, under, and over the surface of the planet), and the atmosphere (the layer of gases surrounding Earth).
Therefore, the correct answer to how the biosphere is a system and the three other parts that make up our biosphere is: a) The biosphere is a self-contained ecosystem; the three parts are lithosphere, atmosphere, and hydrosphere.