What do these signs tell drivers to do when carried by a flagperson in the construction zone?

• Drivers must come to a complete stop immediately.
• Drivers must reduce their speed and prepare to stop.
  Explanation:

  "When a flagperson holds these signs in a construction zone, drivers must follow the displayed instructions. This includes reducing speed and being prepared to stop if necessary."
• Drivers must increase the speed and try to pass through the area.
• Drivers must not stop in the area between these signs.