A 48-year old woman with ductal carcinoma of the right breast has a modified radical mastectomy. After the operation, she has winging of the scapula when she presses her outstretched ARMS against a wall. Which of the following nerves is most likely injured?
A. Axillary B. Long thoracic C. Lower subscapular D. Suprascapular E. Thoracodorsal