A group of populations of different species that live together.

• A. Community
• B. Ecosystem
• C. Population
• D. Habitat

Answer: (A)

The main idea here is the term for all the living species that coexist in one area. A community is made up of the populations of different species living together and interacting in the same place. This includes relationships like competition for resources, predator–prey interactions, and mutualism among plants, insects, birds, and other organisms in a forest, lake, or grassland.

An ecosystem adds the non-living, physical environment to that living community—things like soil, water, climate, and nutrients. A population refers to all the individuals of one species, not multiple species. A habitat is the specific place where organisms live, describing the environment rather than the group of species itself.

So the description of multiple species’ populations living together best matches a community.