To which of the following is abigail adams referring in this excerpt

The excerpt of Abigail Adams is the below:

America may boast that she has accomplished what no power before her ever did, contending with Britain—Captured two of their celebrated Generals and each an Army of thousands of veteran Troops to support them.
—Abigail Adams, letter to John Adams, December 9, 1781

The answer is the American victory at the Battle of Yorktown.

The answer is d.  the north had organized schools, whereas the south had few organized schools.