C. petroleum.
There is a whole wikipedia page dedicated to the petroleum industry of Azerbaijan.
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.
Can we see the opotions plz?
The tourism got back on its feet int int the United States
Answer: Stabilized
