Review Question - QID 218174

A 42-year-old male construction worker is injured at work when a heavy piece of steel falls on his arm and forcefully extends his elbow against resistance. On presentation to your clinic, you note a palpable defect in the antecubital fossa and positive hook test. You recommend repair of his distal biceps rupture using button fixation through a single incision technique. As a part of the informed consent process, you discuss risks of surgery with him. The most commonly injured nerve during this procedure originates from which of the following locations on the brachial plexus?