Which of the following is true for a $Subfamily$?

In which of the following pairs of categories is it more difficult to determine the relationship to other taxa at the same level,thus making the problem of classification more complex?

Read the following statements:
$(i)$ Lower the taxon, more are the characteristics that the members within the taxon share.
$(ii)$ Order is the assemblage of genera which exhibit a few similar characters.
$(iii)$ Cat and dog are included in the same family Felidae.
$(iv)$ Binomial Nomenclature was introduced by Carolus Linnaeus.
Which of the following statements are $NOT$ correct?

Select the correct option for $Panthera$ $leo$,$Panthera$ $pardus$,and $Panthera$ $tigris$.

Given below are two ways of writing the scientific name of Mango. Identify the correctly written name.
$A) Mangifera \, Indica$
$B) Mangifera \, indica$

What is observed when moving from Kingdom to Species?