Answer:
C. They usually focus on retelling historical events.
Step-by-step explanation:
It cant be A because ALL AUTHORS ARE REAL PEOPLE DUH...
it cant be B because it can vary from author to author
idk what D means the tone can be different though
C is the only one that makes sense since all historical events are real therefore making any writing (essay, article or speech) real because history can only be real you cant write something fake and call it history because it never happened.