<span>The answer is B. the assassination of Archduke Franz Ferdinand in Sarajevo
Powder keg in general term is a barrel of gunpowder but it is also used figuratively to refer to the way a small event sets off something much larger. Europe already had many small conflicts but in this event Archduke Franz Ferdinand was a heir to the austrian empire so as he was killed by Sarajevo who was Serbian Austria declared war on Serbia. Serbia was an ally of Russia.So Russia declared war on Austria-Hungary, then Triple Alliance and Triple Entente kicked in, bringing the entire continent to war.</span>
I agree that it would also be D, because the other answers would be just ways to see a scenario and make it best fit for you, whereas D points out what most extremists do.
President Franklin Roosevelt's Annual Message (Four Freedoms) to Congress (1941) Citation: Franklin D. ... The four freedoms he outlined were freedom of speech, freedom of worship, freedom from want, and freedom from fear
Westward expansion also manifest destiny
