Who was the prussian veteran that trained a, ericsson troops at valley forge?

Friedrich Wilhelm August Heinrich Ferdinand Steuben, also referred to as the Baron von Steuben, was a Prussian and American military officer. He served as inspector general and major general of the Continental Army during the American Revolutionary War. He is credited with being one of the fathers of the Continental Army in teaching them the essentials of military drills, tactics, and disciplines. He wrote Regulations for the Order and Discipline of the Troops of the United States, the book that served as standard United States drill manual until the American Civil War. He served as General George Washington's chief of staff in the final years of the war.

The answer would be d) divisions of labor or the fourth option.