What are some reasons to consider San Francisco and Los Angeles as located in separate regions?

A. National boundaries

B. Radio and television station markets

c. Language

D. Climate

The answer is D. climate

I believe it's A because climate changes all over the world, and radio stations and languages have nothing to do with it either, because there are radio and tv stations all over the world and language varies all over the world as well. So there for the answer is A. National boundaries. That mainly stays the same.