C more American workers relocating to urban centers
American colonies were farther away from the King’s rule so they felt a sense of more freedom which over time leads to the Boston Tea Party and then the Revolution.
Or the answer may be they have different types of sickness and environments.
Either or.
The answer is D. Its the only one which would make sense.
<span>new labor union established in the late 1800s sounds right</span>
