Answer:
One of the main influences on the framers of the Constitution was the unwritten democratic constitution under which the Iroquois Confederacy had operated since the 16th century, according to a group of American Indians and scholars
Explanation:
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.