C. The spread of new ideas
It is the most logical answer especially after Gutenberg used the first printing press in Germany so that people could now read the Bible in any language since it was translated from Latin.
This is part of the enlightenment/Scientific Revolution.
ANSWER: C
They could crash into each other they could also do illegal activities
Because they were looking for something that kind if looked like their home.
They created checks and balances so no one branch of government could have more power than any other. For example, Donald Trump is our next president, but Congress and the Supreme Court moderate what he can do.