What are the origin, insertion, and action of the extensor carpi ulnaris?

• A. Origin: lateral epicondyle of the humerus; Insertion: base of the 5th metacarpal; Action: extends and adducts the wrist.
• B. Origin: medial epicondyle of the humerus; Insertion: base of the 2nd metacarpal; Action: extends wrist.
• C. Origin: zygomatic arch; Insertion: angle and ramus of mandible; Action: elevates mandible.
• D. Origin: temporal fossa; Insertion: coronoid process; Action: elevates and retracts mandible.

Answer: (A)