What do flashing alternating red lights on a school bus mean?

• That the school bus is going to speed up.
• That the school bus is going to slow down.
• That the school bus is going to stop to allow students to get on and off.
  Explanation:

  "This is a warning that the alternating red lights are going to begin flashing and the school bus is stopping to allow students to get on or off."
• It can mean any of the above.