What was the main effect, or outcome, of the Mexican War?

A. Slavery was banned in Texas, as it had been in Mexico before the war.
B. Mexico's army defeated the United States forces. California and Texas became part of Mexico again.
C. The United States Army occupied all of Mexico. Mexico would be under occupation for the next fifty years.
D. Mexico turned over its northern territories to the United States. The territory of the United States now reached all the way to the Pacific Ocean.