The community can be defined as the group of different interacting species who live in the same area. Population can be defined as the group of organisms living in a particular area belonging to the same species and having the ability to interbreed. The species can be defined as the group of organisms which can produce offspring with the member of same species of opposite sex, mainly by sexual reproduction.
The ecosystem can be defined as the collection of the interacting populations with the abiotic components present in the same area.
Hence, the answer is option (b) - ecosystem.