Final answer:
The continuation of the anterior division of the lower trunk is the musculocutaneous nerve (option d), which innervates the muscles in the anterior compartment of the arm.
Step-by-step explanation:
The continuation of the anterior division of the lower trunk is the musculocutaneous nerve (option d).
The musculocutaneous nerve is a branch of the brachial plexus and supplies the muscles in the anterior compartment of the arm.
The other options are incorrect: the axillary nerve (option a) innervates the deltoid and teres minor muscles, the ulnar nerve (option b) innervates the muscles of the forearm and hand, and the median nerve (option c) innervates the muscles of the forearm and hand.