<em>B. Register for the draft.</em>
Explanation:
The Selective Service Act was ratified on May 18, 1917. This made it so men ages 21 through 30 were registered for the war draft. This later got changed to men aged 18 to 45.
During this time, the United States was just entering World War I. Not a lot of Americans were joining to fight in the war, which proved to be a problem. Even after making a big deal about this, still not a lot of people joined. A solution needed to be created.
This was when the Selective Service Act was created, as the United States needed soldiers to fight in World War I.
Eyck was a Flemish painter in the early renaissance while Durer was a German Painter and printmaker
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.
#2- Trade emerged as a main source of income.
