There seems to be a typograhical error in option B and C: the word 'community' was repeated twice. However, I've corrected it
Answer: Option B) A community refers to all the populations in an area; a ecosystem includes both biotic and abiotic components
Explanation:
The important difference between community and ecosystem is that the effect of abiotic i.e non- living factors, are considered in an ecosystem, unlike in a community.
Thus, an ecosystem refers to a community of biotic factors i.e plants, animals and microorganisms, interacting together with their non-living environment.
Community, on the other hand, refers to interdependence that occur within a group of plants and animals that occupy a given area. Thus, community considers only biotic factors.