Which of the following statements is consistent with the taxonomic category between Genus and Family?

Which of the following groups of organisms can interbreed?

In the given taxonomic hierarchy diagram, what do "$P$" $\rightarrow$ and "$Q$" $\rightarrow$ represent respectively?

Select the correct statements $(i-iv)$ regarding taxonomic categories.
$(i)$ Each step or rank in the hierarchy is called a taxonomic category.
$(ii)$ Species is a group of individual organisms with fundamental similarities capable of breeding among themselves.
$(iii)$ Taxonomic studies of all known 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.

Classical systematics embodies the concept of classical taxonomists as:

Choose the correct statement regarding biological nomenclature.