PLEAS HELP How do you know that the letter from Harry Truman is a primary source?

A. It was written to members of Truman's immediate family.

B. It was written by Truman himself about current events.

C. It contains information about earlier events.

D. It contains facts about Truman's life.

I believe it is

B.It was written by Truman himself about current events.

Explanation:

I hope this helps!

in 1897, pershing became a tactical officer at west point, and that's where he was given the nickname "black jack." pershing's first name is "john," for which "jack" is a nickname, and he was a white man who commanded black troops. hence "black jack".