question: Q:A 49-year-old man comes to the physician because of a 6-hour history of fever, an itchy rash, and generalized body aches. Ten days ago, he received treatment in the emergency department for a snake bite. His temperature is 38.5°C (101.3°F), pulse is 80/min, and blood pressure is 120/84 mm Hg. Physical examination shows multiple well-demarcated, raised, erythematous plaques over the trunk. There is tenderness to palpation and decreased range of motion of the metacarpophalangeal and wrist joints bilaterally. Urine dipstick shows 2+ protein. Further evaluation is most likely to show which of the following?? 
  {'A': 'Keratinocyte necrosis on skin biopsy', 'B': 'Increased antistreptolysin O titers', 'C': 'Positive ELISA for anti-hemidesmosome antibodies', 'D': 'Increased serum tryptase concentration', 'E': 'Decreased serum complement concentration'},