What Caused the American Civil War

•Economic and social differences between the North and South.

•States versus vederal rights.

•The fight between slave and non-slave state proponents.

a. theta waves. this is because the person is in a light sleep which means the brain waves would show these kind of waves.

the correct answer option is: weapons.

explanation:

tensions rose as the two opposing superpowers competed for 'weapons'.

referring to the cold war (1945-1991), the two superpowers, usa and ussr, experienced a phase of struggle and conflict with each other. these two superpowers considered each other as a threat to their survival and thus opted for policies to strengthen their positions.

the two superpowers never went to war with each other directly but competed for weapons to preserve their positions.