When studying history asking questions and checking other sources will improve ones perspective. what other awareness is necessary?

The best answer for this question would be:

C) To acknowledge primary documents are without bias.

History has been recorded ever since the beginning of time, it is important to look into the primary documents in history and to understand each perspective. Understanding history means, not being biased with the basis of your understanding, every era has a reason why those events had happened.

"a government in which power is divided between state and national levels". federalism is a system of government in which entities such and state and province, share power with the national government.