You are answering a USMLE-style medical question. Question: A 19-year-old man is brought to the emergency department because of severe right shoulder pain and inability to move the shoulder after a fall while climbing outdoors. Examination shows the right upper extremity is externally rotated and slightly abducted. There is loss of the the normal rounded appearance of the shoulder. The right humeral head is palpated below the coracoid process. Sensation to pinprick over which of the following skin areas is most likely to be reduced? Options: A) Medial aspect of the upper arm B) Lateral aspect of the shoulder C) Skin above the clavicle D) Dorsal aspect of forearm and hand Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.