Which of the Following Circumstances Have Been Found Sufficient by Themselves

Which of the following circumstances have been found sufficient by themselves to amount to reasonable suspicion?

A) A driver double-parked within ten feet of a pedestrian in a drug trafficking area.
B) A passenger leaving an airplane appeared nervous in the presence of officers.
C) A driver failed to look at a patrol car late at night.
D) At 2:15a.m. ,a person approached an officer in his police vehicle in a high crime area and told him that a person seated in a nearby car had illegal drugs and a gun at his waist.