Answer:
The Founding Fathers drew heavily upon English philosopher John Locke in establishing America's First Principles, mostly the recognition of unalienable rights, the Social Compact, and limited government.
Brutus' vision of republic is outdated. Diversity of opinion is vital for a republic.
It's necessary for a republic to have people who represent all kinds of people in it. Different classes live different lives, and it's hard for a person who belongs to one class to be aware of the needs, manners, interests of people from a different class. For this reason, diversity is a very important part of a republic.
A republic should <em>NOT</em> be made up of a small group of people who think in a similar way. On the contrary, it <em>should</em> be made up of people from different backgrounds, in order to better represent its people.
B. Americas Declaration of Independence.
A - Because they are a direct link to the events in history
Primary sources are sources that came from that time of history from the same location, time period, and era. For instance, journals from World War II from a French Military leader. These are direct links to that time in history and are the most accurate sources that are presented.
B is incorrect as even without these sources there are other methods to know about history such as secondary sources.
C is incorrect as primary sources are not the only way - again, secondary sources are a thing.
D is incorrect as secondary sources are reliable and can be trusted, but they just aren't as important and well, direct as primary sources.
Hope this helps!