What Was One Way the Mexican-American War Proved Unique in American

What was one way the Mexican-American War proved unique in American history?

A) It was America's first major military defeat on foreign soil and led Americans to adopt a wholly new approach to war in terms of both weapons and military strategy.
B) It was a war in which nearly all Americans consistently supported the conflict and continued to believe it to have been justified even after its conclusion.
C) It was at odds with the idea of manifest destiny that had long influenced other American wars and was driven mainly by religious factors.
D) It was America's first major military intervention outside the United States and the first time that U.S. military forces had conquered and occupied another country.
E) In terms of the percentage of combatants killed, it had the lowest death rate of any war in American history and, thus, made more Americans likely to join the military in the next war.