How should a motorcycle rider approach a vehicle that is turning left in front of them?

Answer: C — Slow down and prepare to stop if necessary

A motorcycle rider should slow down and prepare to stop if necessary when approaching a vehicle that is turning left in front of them. This action allows the rider to assess the situation more effectively, as left-turning vehicles can create a sudden hazard. Slowing down provides the rider with more time to react to the driver's actions, potentially avoiding a collision. In such a scenario, the vehicle may not see the motorcycle or may misjudge the distance and speed of the oncoming motorcycle, leading to a dangerous situation. By slowing down, the rider can ensure they have enough time to stop or maneuver safely, should the vehicle attempt to turn in front of them unexpectedly. Maintaining the same speed or speeding up could increase the risk of an accident, as it leaves less time for both the rider and the left-turning driver to react appropriately. Similarly, signaling the vehicle to proceed could be misleading and may not provide any benefit, as the driver might misinterpret the signal. Therefore, slowing down and being prepared to stop is the safest approach in this situation.