Which statement is an example of evidence a historian could use to support claim about the american civil war

B - The Emancipation Proclamation freed slaves only in states that had seceded from the Union.

This is a factual statement that a historian could use. Options C and D are opinions and option A is non-factual and non-committal.

c 3 branches because idk why they had 3 well when:

you think of it there are still contrys with 3