Question

Which is the best way to measure public opinion?

Answer 1

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. 

Answer 2

question 2 answer is b