What is the genus of potato and brinjal?

The correct sequence of the various taxons while naming an organism is:

What is '$P$' in the given figure?

Assertion $-A$: The term 'genus' is a single term.
Reason $-R$: $A$ genus may have one or more species; a species may be a single or a combined term.

Select the correct statements $(i-iv)$ regarding taxonomic categories.
$(i)$ Each step or rank in hierarchy is called taxonomic category.
$(ii)$ Species is a group of individual organisms with fundamental similarities capable of breeding among themselves.
$(iii)$ Taxonomic studies of all unknown organisms have led to the development of common categories like kingdom,phylum or division,class,order,family,genus and species.
$(iv)$ Lower the category,greater is the difficulty of determining the relationship to other taxa at the same level.

Which of the following features are not shown by scientific names of various organisms?