Definition of ecosystem is

Ecosystems can be small, like a pond, or large, like a forest. They can be found on land, in the water, or in the air.

Ecosystems are important because they provide us with food, water, and air. They also help to regulate the climate and protect us from natural disasters.

Here is a brief explanation of each option:

• Option B: The abiotic component of a habitat. The abiotic component of a habitat is the non-living part of the environment, such as air, water, soil, and sunlight.
• Option C: The part of the earth and its atmosphere which inhibits living organisms. This is a very broad definition of an ecosystem, and it does not include the interaction between organisms and their environment.
• Option D: A community of organisms interacting with one another. This is a good definition of a community, but it does not include the non-living environment.

I hope this helps!