How do the police or other enforcement officers signal for you to pull over and stop your vehicle immediately?

• By driving their vehicle with emergency lights flashing and/or sirens on behind your vehicle
• By using hand gestures from the side of the road
• They are not allowed to stop your vehicle
• Both A & B
  Explanation:

  "Police or enforcement officers can signal for you to stop by either using flashing lights and/or sirens behind your vehicle, or by using hand gestures from the side of the road."