The correct answer is the North because of its well-established government.
Before the Civil War, the United States already had a well-established government for over 70 years. However, the South, had to develop their own system of government, own military forces, and own supplies before they could successfully fight the Union army.
The Reign of Terror came to an end, because the man who had started the Reign of Terror (Robespierre) was executed. The Reign of Terror also came to an end, because nuns had been executed because they did not want to give up their monastic vows and they were very calm during the execution, so this shifted the mood in Paris, probably making the general population realize that the mass executions were futile.
Option D is the correct one, Woman's suffrage and the rights of African Americans <span />
It seems like B is the most likely answer, considering it's really the only one that applies to democracy.