Yorktown description and event?

Siege of Yorktown, joint Franco-American land and sea campaign that entrapped a major British army on a peninsula at Yorktown, Virginia, and forced its surrender. The siege virtually ended military operations in the American Revolution.

Start date: September 28

End date: October 19, 1781

answer; ///i believe that the correct answer is (b); ///the candidate must be a native born american citzen;