Hint: The term Biocoenosis differentiates "life assemblages" i.e. the original living community which are living together at one place and at a given time. Alternatively, Biocoenosis is a congregation of fossils or a community of a definite time. The use of the term Biocoenosis has declined in the late 21st Century.
The word Biocoenosis was coined by Carl Mobius in 1877. It describes the interaction of organisms which are living together in a specific habitat commonly known as a biotope.
Biocoenosis is also known as a biological community which is defined as the assemblage of several organisms living in a closely integrated community. The organisms in this community occupy the same specific biotope or habitat.
According to the concept of biocenosis, the ecological communities take in various forms which can be classified into three categories listed below:
1.Zoocenosis used for the faunal community,
2.Phytocenosis used for the flora community,
3.Microbiocenosis used for the microbial community.
Biotic communities differ in size. The larger communities contain the smaller ones within themselves. Species interactions between communities are evident in their food or feeding relationships. The method of defining biotic communities is to map out the food network of the communities in order to identify which species feed upon which other species and then determine the system boundaries.
Hence, the correct answer is option (B)
Note: An ecosystem was first defined by Tansley in 1935. It is a biotic community or a biocenosis along with the physical environment or a biotope. In ecological studies, the term biocenosis emphasises more on the relationships between species living in a particular area. These relationships within various species are considered additionally to the interaction of each species with their physical environment.