Which components should be connected by castle nuts and cotter pins?

The correct choice identifies the pitman arm, drag link, and tie rod as the components that should be connected using castle nuts and cotter pins. These components are integral parts of the steering system in a vehicle.

Castle nuts provide a secure fitting that holds these parts in place while allowing for some movement, which is essential for steering. The cotter pins serve to prevent the castle nut from loosening, ensuring that the components remain secured during operation.

The pitman arm transmits the rotational movement from the steering wheel to the drag link, which connects to the tie rod that ultimately facilitates the turning of the wheels. This connection must be secure to ensure safe maneuvering of the vehicle, making the use of castle nuts and cotter pins crucial in maintaining the integrity of the steering system.

In contrast, the other choices include components that do not specifically require this type of fastening for their connections. For instance, while leaf springs and shocks do play a role in suspension, they typically use different types of mounting hardware. The steering wheel and steering column are connected using different mechanisms, and while axles and wheel bearings are critical to the vehicle's functioning, they are also fastened in ways that do not primarily involve castle nuts and cotter pins.