After the Archduke's assassination, all the great powers of Europe began declaring war on one another. This is an example of which idea:
A. Alliance systems
B. Militarism
C. Imperialism
D. Nationalism

B. Militarism

Explanation:

Through the process of elimination:

Alliances are based on certain powers helping each other, nationalism is a strong sense of loyalty and pride for one's nation, and imperialism is the act of conquering a land to expand an empire. :)

The concept of militarism:

Basically a strong sense that a group of people or nation should establish and maintain a strong military, which is used for the nation's interests, war, defense, and more.

haitian revolution slaves initiated the rebellion in 1791 and by 1803 they had succeeded in ending not just slavery but french control over the colony

a marriage ending by the death of a husband or wife.

explanation:

i don't see your choices but i'm just gonna give you my answer.