Answer:
<em><u>C. Common knowledge</u></em>
Explanation:
Common knowledge is any information that is fully known by most people and does not need any citation since it is part of the collective knowledge, and it varies depending on culture, region, age or country.
For example, <em>"On July 4, 1776, the Independence of the United States was declared"</em> does not need citation because it is common knowledge in the United States.
Any information, ideas or texts by experts about a specific topic must be cited because they are conclusions and original work.