Which taxonomic term may be suggested for any rank in the classification?

$A$ group of organisms with fundamental similarities is known as:

Match the following taxonomic categories in Column-$A$ with their respective examples in Column-$B$:

$1$. Species	$P$. Solanum
$2$. Genus	$Q$. Leo
$3$. Family	$R$. Polymoniales
$4$. Order	$S$. Felidae

Describe the importance of nomenclature.

Assertion $-A$: Carolus Linnaeus is known as the father of taxonomy.
Reason $-R$: The classification system proposed by him is still accepted today after some modifications.

Plants belonging to different classes,with a few similar characters are assigned to a category called