Answer:
Correct answer is diary entries by President Carter
.
Explanation:
Third and fourth options are not correct as first of all textbook and encyclopedia are not a primary, but a secondary historical source.
On the other side, diary entries are the best primary source because are written sources from the perspective of someone who participated in certain events, in this case president Carter.
Second option is not correct option, but after the diary journal articles would be also important as are written in the period when certain events happened.
From what i can actually read it look to be correct.
Answer: Farmland and superior military leadership. The southearn soldiers could live on the land much better than the north.
Explanations: North was based on factory’s mostly and South wanted slaves and they did plantations and stuff so that’s why they wanted it.
if I'm not wrong, it is executive power