Grant Was Arrested for Unlawful Possession of a Firearm, a Misdemeanor

Grant was arrested for unlawful possession of a firearm, a misdemeanor in New York State. He is involved in a custody battle with his ex-wife and he brought the gun with him to scare her into letting him see his daughter more often. They got into a shouting match and he pulled the gun out. Grant was arrested and he pled guilty to disorderly conduct, a handgun violation, and was given probation. You are Grant's probation officer and you stop by the police station to visit an officer on "gun amnesty and buy back day." You see Grant turning in a handgun. Although he is indeed turning it in, it is a violation of Grant's conditions of probation to be in possession of a firearm. What is your best course of action?

A) Change Grant's probation to a suspended sentence.
B) Make Grant forfeit the money he receives from the gun amnesty program.
C) Revoke Grant's probation on the spot and have your friend arrest him.
D) Notify Grant that his probation may be revoked and his conditions may be changed.