Which statement best explains the connection between the post-Civil War problems the US Army faced and the ease of Cathay's military enrollment? A. The US Army was so desperate for more African American soldiers to guard the Mexican border that it was willing to accept women into the units. B. The issues raised by the creation of the Buffalo Soldiers, combined with a push for western expansion, allowed women entrance into the newly created regiments. C. The problems caused by Native American warriors, combined with a lack of monetary resources, spurred the US Army into militarizing civilians. D. The US Army was so in need of additional troops to secure the West that it did not screen and examine African American recruits as thoroughly as it should have.