What must you do when you see a police car with its lights flashing behind you?

Answer: B — Pull over to the side of the road and stop

When you see a police car with its lights flashing behind you, it is essential to pull over to the side of the road and stop. This action is required by law and is critical for ensuring the safety of both the driver and the officers attending to the situation. Stopping allows law enforcement to approach your vehicle in a safe manner, assess the situation, and communicate with you effectively. Choosing to speed up and get away poses significant risks, including endangering yourself, other motorists, and the police officers involved. Continuing to drive until reaching your destination would disregard the officer’s request for you to stop, which could lead to further legal repercussions. Waving goodbye does not address the situation appropriately and would be considered disrespectful and dangerous. Therefore, safely pulling over is the correct and legally mandated action to take.