Answer:
A. Specific Detail
Explanation:
It is definitely not humor or assertion, which is a confident, forceful statement. I don't see it as simplicity because that is plain, natural, or easy to understand. When writing a thesis statement, your topic needs to be strong and to the point, which is more a specific detail. In this case, it is a specific detail about the narrator.
Answer:
C.) A personal letter written by a civil rights leader in 1966
"slow and steady wins the race."