Which of the following items must function properly during a road test?

The correct answer is that brake lights, taillights, and turn signals must function properly during a road test. These lighting signals are crucial for communication on the road, as they inform other drivers of your intentions, such as stopping, turning, or changing lanes.

Proper functioning of brake lights is vital because they indicate to drivers behind you when you are slowing down or stopping. Taillights help other vehicles see you from the rear, especially in low visibility conditions, while turn signals are essential for indicating your intended direction to ensure safe lane changes or turns.

While the other items listed, such as windshield wipers, headlights, and engine power, are important for safe vehicle operation and may be checked during a road test, the specific requirement for brake lights, taillights, and turn signals is critical for safe driving and is directly related to obeying traffic laws. Ensuring these lights are operational demonstrates a driver's awareness of road safety and their responsibility to communicate effectively with other road users.