Why do you think geographers divide the eastern u. s. into four subregions

The American East contains the entire Atlantic coast of the United States. This means that there are marked differences between the latitude of one place and that of another, both located on the east coast.

For example, Miami and Boston are located in the American East, but these cities have completely different climates, as well as totally different cultures and idiosyncrasies, originating in the different demographic components of both cities.

The differences of climate, added to the cultural and historical differences of each region, causes the geographers to establish differences between the different areas of the American East, which they divide into 4 sub-regions: New England, Mid-Atlantic, South-Atlantic and East South Central.

a is the answer i believe.