What ‘secret item’ did Washington get that convinced him he could win at Princeton?

The correct answer to this open question is the following.

Although there are no options attached, we can say the following.

Thet ‘secret item’ that Washington got that convinced him he could win at Princeton was intelligence information that allowed him to know that British soldiers were extremely spread in New Jersey, and he thought this represented a big advantage for the Continental Army troops. So General Washington sent his troops to Ramapo Mountains and recruited more people to attack the British.

That is how, on January 3, 1777, the continental Army, led by General George Washington, defeated the English troops in the Battle of Princenton.