How does periodization historians study past

Periodization refers to a process by which historians organize long periods of time into eras based on their similar characteristics. This type of organization serves several purposes. It allows historians to create more manageable categories, which then allow them to study them in a more accessible way. It also allows them to highlight the commonalities and differences of various time periods. Finally, periodization is also a useful way to see how patterns of behaviour and culture have changed through time.

a

explanation:

the answer would be:

b. race