The answer is Rutherford B. Hayes
B, manifest destiny, they believed that they had the god given right to expand west
They constitution protect slavery in a way that you can pay people to work for you but you cannot make them do it they have to be their on their own consent and it proctect slavery because people were dying from being overworked and underpaid.
The best way to measure public opinion is through opinion polls - B
With opinion polls you get an idea what is the general idea about a certain topic from the public, as you usually get a high enough sample to deduce the relevant information.
To answer your second question I would say it is either B or C as being a sole proprietor usually makes you subjec to being a small business or you're forced to use factors of production less efficiently.
