Which of the following is a taxon?

Statement $S$: The family $Columbidae$ includes pigeons and doves,which consist of various genera and species.
Reason $R$: $A$ family is a category formed by a group of closely related genera.
$(a)$ Both $S$ and $R$ are true,and $R$ is the correct explanation of $S$.
$(b)$ Both $S$ and $R$ are true,but $R$ is not the correct explanation of $S$.
$(c)$ $S$ is true and $R$ is false.
$(d)$ $S$ is false and $R$ is true.
$(e)$ Both $S$ and $R$ are false.

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

Identify the correct terms for the following statements:
$(i)$ The science of classifying all organisms into different taxa based on their characteristics.
$(ii)$ The system of naming organisms following specific rules.
$(iii)$ The branch of science that includes the study from populations to the biosphere.
$(iv)$ The structure formed by the combination of all taxonomic categories.

$A$ scientist who made a significant contribution in the field of classification is

$A$ person who studies the origin,evolution,and variations in plants,as well as the classification of plants,is called a: