Jack Was Hanging Out in a Gang-Infested Neighborhood

Jack was hanging out in a gang-infested neighborhood. Officer Knight watched Jack walk up to a car in the parking lot of a fast-food place. From where Officer Knight's police car was located about 50 feet away, it looked like Jack had started an argument with the driver of the car. Officer Knight exited his car and walked rapidly toward Jack. When he was 10 feet away, he yelled at Jack to step back from the car and put his hands up. Jack took one look at Officer Knight and ran the other direction. Officer Knight saw an unidentified object in Jack's hand that he thought might be used as a weapon, so he fired two shots. One shot missed but the other struck Jack in the leg. Immediately after arriving at the spot where Jack fell, Officer Knight searched him and found 3 baggies of marijuana in his pocket. Did Officer Knight have the right to stop Jack for questioning?

A) Yes, Officer Knight is allowed to stop anyone who is behaving suspiciously and verify that what they are doing is legal.
B) Yes, the specific facts that Officer Knight observed would lead any reasonable officer to believe that Jack was about to start a fight.
C) No, Officer Knight does not have the right to stop Jack unless a crime has occurred.
D) No, Officer Knight did not have probable cause to arrest Jack at the time he yelled at Jack to step back and put his hands up.