45. A 26-year-old weight lifter felt a sharp pain in the neck, radiating to the dorsal aspect of the forearm during his workout. Over the next few days he noted progressive numbness of the thumb and index finger. He also complained of decreased ability to perform bicep curls. On examination by his primary care doctor, a markedly diminished biceps reflex was found. Which of the following is the most likely cause of the patient's problem? (A) Facture C5 vertebra (B) C5-C6 disc protrusion (C) Facet syndrome at C5-6 (D) Compression of the C5 nerve root by an osteophyte