A, the black plague. This is because the mongols would invade and actually use people infected with the plague to throw over walls of towns to infect the people inside.
Answer:
D. it unified people and showed how kindness and bravery can overcome fear to respond to terrorism
I believe that it most likely would be D.
Prior to 1812 most Americans lived on the East Coast of the United States, since the US had not yet truly began its expansion westward and to the North west at this time.
He wrote books based on his experience in World War 1