What is the term given to the groups of organisms arranged at different levels of classification?

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.

The order $Primata$ contains:

Which of the following represents the correct sequence of decreasing order of diversity?

Statement $A$: $A$ genus includes more than one species.
Reason $R$: An extinct human species is $Homo\, erectus$.
Which option is correct for Statement $A$ and Reason $R$?

What different criteria would you choose to classify people that you meet often?