What is the term used to describe a functional unit of nature in which living organisms interact with one another and the physical environment surrounding them?

Ecosystem

(a) Biosphere: The biosphere refers to the zone on Earth where life exists. It encompasses all ecosystems, organisms, and their interactions, extending from the highest reaches of the atmosphere to the depths of the oceans. The biosphere includes all living organisms and their habitats, including plants, animals, microorganisms, and their physical environment.

(b) Ecosystem: An ecosystem refers to a specific area or environment where living organisms interact with one another and with the non-living components of their environment. It involves a complex web of interactions between plants, animals, microorganisms, and their physical surroundings, including factors like climate, soil, water, and air. Ecosystems can vary in size and can be as small as a pond or as large as a forest.

(c) Environment: The environment refers to the external surroundings or conditions in which living organisms exist. It encompasses both the biotic (living) and abiotic (non-living) factors that influence the organisms in a given area. The environment includes elements such as air, water, soil, climate, and the presence of other living organisms.

Given the options, the most suitable answer to the question is:

(b) Ecosystem, as it specifically describes the functional unit of nature where living organisms interact with each other and the surrounding physical environment.