The answer for this question is B
The main reason that New Mexico faced such difficulty in becoming a state in the 1800s was because Congress was unwilling to accept New Mexico's application for statehood. People were suspicious of the area's inhabitants and their varying background.
Schools in the United States started integrating in the 1950's as a direct result of the Brown v Board of Education Supreme Court ruling.
The Civilization got it start in China at ~~ The Yellow and Yangtze River Valleys.