<em><u>Answer:</u></em>
B) the acquisition of California and New Mexico.
<em><u>Explanation:</u></em>
The U.S.- Mexican War tremendously affected the historical backdrop of the two nations. For the United States, this was the country's first remote war battled for the most part on outside domain. It included different armed forces, long supply lines, a vast scale land and/or water capable arriving of troops, and it gave the main experience of involving an outside capital and setting up a military government for an outsider populace.
Mexico had lost around 33% of its region, including almost all of present-day California, Utah, Nevada, Arizona and New Mexico.
The correct cause-and-effect relationship which led to World War II is the aggressiveness of Japan, Italy, Germany and Treaty of Versailles’ that caused resentment for the German. Its effect is that this led to the use of nuclear weapons during the war and later led to the Cold War.
Freed slaves from the U.S.