Tire chains are placed on which part of the vehicle to improve traction for downhill braking?

Answer: C — Trailer wheels

Tire chains are primarily placed on the drive wheels of a vehicle to improve traction, especially in challenging conditions such as snow or ice. While placing chains on trailer wheels can provide some benefits, the key point in the context of downhill braking is that the drive wheels are primarily responsible for the vehicle's ability to decelerate effectively. For most vehicles, this means the chains would typically go on either the rear wheels (in case of rear-wheel drive) or the front wheels (in case of front-wheel drive). Chains help to prevent slipping and enhance grip, which is crucial during downhill maneuvers where maintaining control is vital. In many professional driving scenarios, it’s considered best practice to place chains on the drive wheels to maximize traction when descending or navigating through slippery conditions. Therefore, while chains can be used on trailer wheels for increased stability, the most effective strategy for improving braking and traction during downhill travel is to focus on the drive wheels. This underscores the importance of understanding the role of different wheel placements and how they affect vehicle performance under various road conditions.