How should a motorcyclist position their mirrors?

Answer: D — To see as much as possible of the adjacent lane and a substantial part of the lane behind them.

Positioning mirrors correctly is crucial for a motorcyclist’s safety and awareness on the road. The correct choice advocates for the optimal adjustment of mirrors to maximize the field of vision, allowing the rider to see both the adjacent lane and a significant portion of the lane behind them. By setting the mirrors to cover these areas, a motorcyclist can effectively monitor surrounding traffic, including vehicles that may be in neighboring lanes or approaching from behind. This comprehensive view helps in making informed decisions regarding lane changes, overtaking, and overall situational awareness. Being able to see vehicles in the adjacent lane enables timely responses to potential hazards, such as a vehicle preparing to merge into the motorcyclist’s lane. In contrast, just focusing on the adjacent lane or the lane behind limits the rider's awareness and increases the risk of missing critical information about surrounding vehicles. Avoiding mirror use entirely in heavy traffic can lead to dangerous circumstances as situational awareness decreases, leaving the rider vulnerable to potential collisions or other hazards.