You are asked to see a 72-year-old woman with several weeks of spontaneous neck pain and pain in the area of the right scapula. She has no history of trauma or arm/shoulder injury. She describes...

You are asked to see a 72-year-old woman with several weeks of spontaneous neck pain and pain in the area of the right scapula. She has no history of trauma or arm/shoulder injury. She describes occasional numbness running down her right arm anterolaterally, which stops proximal to the wrist. On exam, you appreciate slight biceps weakness and deltoid weakness on the right. X-ray film of the right shoulder and humerus shows no evidence of fracture or bony deformity other than degenerative changes in the cervical spine. What is the most likely diagnosis?

A. Median nerve injury

B. C5 radiculopathy

C. Axillary nerve injury

D. Musculocutaneous nerve injury

E. Upper brachial plexus injury