The United States Congress is specifically forbidden from some actions because the Congress might be wrongly influenced to make certain changes that can effect the general people of the country. The constitution might get affected and the country might lose the virtues on which the founding fathers created the constitution.
The president who did that was richard nixon ur welcome.
This is a personal question, which means that only you can answer it. However, I can give some examples that might help guide your work.
An example of a primary source that you might encounter in your own life is that of a news article. As this article is likely to be written by a reporter witnessing the events, it can be considered a primary source. On the other hand, an example of a secondary source would be a non-fiction book that talks about a historical event. This is because such a book would give a second-hand account of an event based on historical information.
The answer is most likely C. Most of the men were either drafted or volunteered for war.