Independent front and rear suspension systems:

Independent front and rear suspension systems are designed to enable each wheel on a vehicle to move vertically without being affected by the movement of the other wheels. This design enhances ride quality, handling, and traction, as it allows each wheel to respond to road conditions independently. For instance, if one wheel encounters a bump, the others can remain in contact with the road, maintaining stability and control.

The other options don't accurately depict the function or purpose of independent suspension. In contrast, some might suggest that an independent system would connect both sides to a single axle, but that description applies to solid axle systems rather than independent ones. Additionally, independent suspension systems are actually quite common in modern passenger cars, contradicting the assertion that they are rarely used.