Answer:
B) the sinking of the Lusitania.
Explanation:
According to the Library of Congress, a German submarine sabotaged the British-owned luxury steamship Lusitania on May Seventh, 1915, and in the incidence killing withe the British passenger, 123 Americans lost their lives. this event has changed the course of world war because it gave the Neutral United states reason to enter the war from the allied side.
It collapsed because of cold war and also corruption.
<span>Experiments in which all variables are identical except for one are called controlled experiments. This where an observer tests his hypothesis by looking on changes that were brought about by one variable. The results are always dependent on one adjusted variable.</span>
