Which muscle performs the action of extending and abducting the wrist?

The extensor carpi radialis is the muscle responsible for extending and abducting the wrist. When this muscle contracts, it helps to lift the back of the hand up while simultaneously moving it away from the midline of the body. This combination of actions allows for a broader range of motion at the wrist joint, facilitating activities that require wrist extension and lateral movement, such as throwing or grasping objects.

In contrast, the flexor carpi radialis and flexor carpi ulnaris primarily function to flex and adduct or abduct the wrist, respectively, but they do not produce extension. The triceps brachii, while involved in elbow extension, does not have a significant role in wrist movement. Thus, the specific actions and functional anatomy of the extensor carpi radialis make it the correct choice in this context.