Final answer:
The biosphere encompasses all areas of Earth where life exists, incorporating elements of the lithosphere, hydrosphere, and atmosphere, and is a critical concept in ecology for understanding the interplay of living organisms with their environment. option a is correct.
Step-by-step explanation:
The biosphere is defined as the part of Earth that contains all living things, including the air, land, surface rocks, and water where you can find life. This encompasses everything within the realms of the lithosphere (the crust and upper mantle of the Earth), hydrosphere (all water bodies), and atmosphere (the layer of gas surrounding Earth) that support life. The biosphere extends from about 11,000 meters below sea level up to approximately 15,000 meters above sea level.
The concept of the biosphere is a fundamental aspect of ecology, and it is a critical component in understanding how living organisms, including plants, animals, and microorganisms, interact with each other as well as with their nonliving environment. This interconnection of biotic (living) and abiotic (nonliving) factors forms various ecosystems within the global biosphere.
Presently, Earth is the only known planet in our solar system to possess a robust biosphere that creates observable planet-scale changes, such as those found in the composition of our atmosphere and the spectrum of light reflected from our planet.