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.
This type of advertising is called Testimonial and it's using the technique known as Celebrity Endorsement. In testimonial advertising the message is saying "this person says this product/politician is good", and the celebrity endorsement refers to the link between the product and the famous person. This technique is mainly used in sports, when famous athletes only wear one type of brand, they are telling you "this product is good because this famous person always uses it".
Maintaining balanced power between Nations.
Hope this help you out!!!! : )
The Great Awakening, because it was a religious revival that encouraged people to go back to church and join a religion.