What should you do if you see an emergency vehicle with its siren approaching?

Answer: B — Pull your vehicle to the curb and stop in a safe location

Emergency vehicles use their sirens to inform other drivers that they are responding to an emergency. It is important for drivers to pull over and stop in a safe location to allow the emergency vehicle to pass. Options A and D are incorrect because ignoring or speeding up to get out of the way can cause delays or potentially dangerous situations. Option C is also incorrect because moving to the left side of the road may not provide enough space for the emergency vehicle to pass. By pulling over and stopping, drivers are ensuring the safe and efficient passage of the emergency vehicle.