Geographers have divided the study of geography into . A.
five fundamental regions
B.
six essential elements
C.
seven topics
D.
four key themes

I'm guessing  a. diverse  because it shows a wide variety of many things.

It's probably because the earth is actually tilted and is not straight when orbiting the sun. that's why when it's winter here, it's summer in the southern hemisphere. in the wintertime in the northern hemisphere, it's colder here because it's tilted away from the sun and the southern hemisphere is tilted closer to the sun (i believe this is the case anyways)