How did the american and mexican war affect americans and mexicans living in the southwest ?

Mexicans in the now occupied lands were to be protected under the laws of the United States and the treaty they retain the right to your language religion culture their property and land was protected by the law .as for citizenship they were offered one of three options declared your intent to retain Mexican citizenship leave to Mexico or become a citizen of the US by doing nothing

It is c because it shows how the author is stating their own oppinion about the protagonist

Transcontinental railroad was the most effective way to travel.