It would be primarily "The Church and the Crusades" that <span>played a significant role in uniting the kings and people of Europe, since adhering to religious principles back then was the norm for most. </span>
C) Ten Percent Plan ....Hope it helps, Have a nice day?
I believe the correct answer is: The theory of universal
gravitation.
The famous anecdote of an apple falling from a tree and
striking the head of the young Sir Isaac Newton which stroke the great idea,
helped him come up with The theory of universal gravitation, as a concept and
ever present force.
