This depends on if a refers to the current government.
If it is, then the answer is D. none of the above
However, the articles of confederation, america's first government, was the first thing that Americans did after the war, so the answer could also be A
The Appilachian mountains was the greatest barrier, because it was crawling with Indian's that may have made them turn back.
Explanation:
the answer is A trust me I test took my unit test and passed with a 100