The answer is A. Baron Von Steuben, He trained the American troops of the revolutionary war. Baron Von Steuban was a skilled Prussian former soldier.
With these answer choices you can Eliminate two choices right off the bat, Namely Thomas Jefferson and Ben Franklin, Both signed the Declaration of independence, Thomas Jefferson was also an Inventor while Franklin was a Printer.
Now Jean-Jacques Rousseau was a Genevan writer, philosopher and composer