The correct answer is B. At the Battle of Trenton, George Washington lead his troops across the Delaware River, which was frozen. No one expected that, as it was a risky move to cross a frozen river in winter, with a snow storm whipping the soldiers (in fact, 2 soldiers died of exposure during the march).
Due to that, Hessian forces weren't guarding that flank, and the entrance of the American forces was a success.
The Battle of Trenton was a key moment of the American War of Independence, as it showed to the American population that the victory was possible.
