If a highway has a sign indicating "No U-turn," what does it mean?

Answer: A — You cannot turn around on this highway

The indication of "No U-turn" on a highway signifies that drivers are prohibited from performing a U-turn at that location. A U-turn involves turning the vehicle 180 degrees to go in the opposite direction. Such maneuvers can be dangerous, particularly on highways where traffic is typically moving at higher speeds and where visibility may be limited. The sign serves to improve safety by ensuring that all vehicles maintain a consistent flow of traffic and reducing the risk of accidents that could occur from making sudden and unexpected turns. This rule helps eliminate potential hazards for both the driver making the turn and other road users. The other options suggest scenarios that don't align with the purpose of the "No U-turn" sign. It is not about being required to turn at the next intersection, specifying only left turns, or allowing U-turns in emergencies—all of which do not accurately reflect the restriction that the sign imposes.