Who was Baron Friedrich von Steuben
A. a former Prussian captain who turned a disorderly group of American recruits into skilled soldiers
B.the Hessian commander of British troops in the South who lost the battle at Yorktown
C. the Frenchman who became a general on Washington's staff and his lifelong friend
D.a young German officer on Washington's staff who captured a British fort during the battle at Yorktown
