How do "Tripod" CV joints differ from "Rzeppa" joints?

Tripod CV joints are designed differently from Rzeppa joints primarily in their structure, which makes the fourth choice the correct one. Tripod joints consist of three roller bearings that facilitate movement. This configuration allows for a greater degree of angularity and flexibility compared to other joint types. The use of three roller bearings also helps to reduce friction and increases load capacity, which is essential for driving dynamics and handling.

When comparing the two joint types, Tripod joints generally exhibit unique characteristics that cater to specific needs in a vehicle's drivetrain, especially in terms of handling forces during turns and providing smooth movement. Rzeppa joints, on the other hand, typically have a sphere-shaped inner race with multiple grooves, which allows for flexible motion but is structured differently than the Tripod joints.

The other options mention aspects such as load capacity, suspension handling, or application to heavy-duty vehicles, but these factors can vary depending on specific designs and applications of both joint types. The distinct feature of having three roller bearings sets Tripod joints apart in how they manage power transfer and flexibility.