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.
A. Putting federal laws into effect
Economists are the social scientists that focus their studies on scarcity, resources and profit motives. The economists not only follow the pattern in which the economy of a country is going, it also gives plans to improve the economy. They are a very important part of any civilized society. I hope it helps you.
Maize was the first crop domesticated in mesoamerica, it was frequently grown with squash and beans the earliest evidence of this is in guila naquitz in mexico
