At the End of the Mexican-American War

At the end of the Mexican-American War,

A) most Americans living in places that were previously part of the U.S. and were now part of Mexico chose NOT to become Mexican citizens.
B) most Americans living in places that were previously part of the U.S. and were now part of Mexico chose to become Mexican citizens.
C) most Mexicans living in places that were previously part of Mexico and were now part of the U.S. chose NOT to become American citizens.
D) most Mexicans living in places that were previously part of Mexico and were now part of the U.S. chose to become American citizens.