Which of the following is a sign of a defective suspension system?

A sign of a defective suspension system is often associated with excessive noise during acceleration. This noise can come from worn-out components within the suspension system, such as struts, shocks, or bushings. When these parts are not functioning properly, they can produce clunking or grinding sounds due to the excessive movement or wear of the components, indicating that the suspension is not absorbing bumps or uneven surfaces effectively. This can impact the vehicle's overall handling and comfort, making it essential to address any unusual noises promptly.

The other options do not indicate issues with the suspension system. Frequent tire rotations are a normal maintenance practice that extends tire life and ensures even wear. A comfortable ride typically signifies that the suspension system is working well to absorb shocks and provide a smooth driving experience. Stable handling reflects a well-functioning suspension system that maintains tire contact with the road, contributing to safe and responsive driving.