Question

Which of the following has a real existence?
A. Phylum
B. Class
C. Genus
D. Species

Answer 1

Hint:
Before we proceed into the problem, it is important to know the definition of Taxonomic hierarchy.
Some general categories that may apply include Kingdom, Class, Order, and Family. Each of these groups has a slightly different set of characteristics that make them unique. For example, the kingdom includes Animalia (animals), Plantae (plants), Fungi (fungi), and Protista (protists).

Complete step by step answer:
The practice of putting diverse creatures into successive tiers of biological concept, either in decreasing or rising order, from kingdom to species and vice versa, is known as a taxonomic hierarchy.
The important taxonomy hierarchy includes Kingdom, Phylum, Class, Order, Family, Genus and Species.
At the bottom of the taxonomic hierarchy, there present a tier called species.
Phylum, Class, and Genus are taxonomic groupings that only exist theoretically for the benefit of expediency, whereas species have an actual existence and are defined as a group of interbreeding populations.
Cats, for example, are real-life species that are members of the genus Felis and family Felidae, but they are not an entity in the biosphere.
Therefore, Species have a real-life existence.

Option ‘D’ is correct

Note:
The only taxon where we discover the true or true existence of the specific organism is species. This happens because "species" is the lowest taxon, and every other taxa are built on top of it. Interbreeding happens at the species level as well.