I think it's A. The admission of Missouri as a slave state was controversial in the Senate because t<span>he Senate was a Pro-Slavery</span>
Cecilia is an observational researcher, or more commonly known as a field researcher. Observational researchers observe their subjects in their natural state and do not need to any form of experimentation. They gather information from their observations but do not intervene on any of the actions of their subjects.
Answer: A
C and D are wrong right off the bat because building a railroad during bad whether is not enjoyable or easy, plus it took seven years to build so it was not fun
It is not B because the passage does not state anything about people preferring to ride in wagons to riding by train
So it is A because truly it was a difficult process