Hint: Binomial nomenclature is a system of nomenclature in which all living organisms are given specific scientific names. Scientific names consist of 2 parts, first part is genus name and the second part is the species name.
Complete answer: When a name of a species has the same words in both genus and species are called tautonym.
Examples of tautonyms are- Gorilla gorilla is for gorilla, Vulpes vulpes is for red fox , Rattus rattus for black rat .
Two different organisms can have similar species names but their genes must be different. Example: Pinus glabra (Cedar pine) and Ilex glabra (inkberry).
Species can be used for the same or another genus again
Hence the correct option is: A) Can be used the same as genus.
Note: Organisms are given scientific names so that they can be recognised globally with similar names.
Universal rules while writing scientific name are:
1. Biological names are generally written in italic format and the name is given in Latin language irrespective of their origin.
2. When the words are hand written, they are separated by underline and when printed, it should be in italics, to indicate their latin origin.
3. The first word denoting the genus and it starts with a capital letter. Species names start with small letters.
4. Name of the author is mentioned at the end in an abbreviated form.
Example: Mangifera indica Linn is for mango.
5. All the organisms from the plant and animal kingdom have species as their lowest category.
6. Organisms are classified in sequence of : kingdom, phylum or division (for plants), class, order, family, genus and species