question: Q:A 10-month-old girl is brought to the physician because of a 4-day history of irritability and a rash. Her temperature is 37.7°C (99.9°F). Examination of the skin shows flaccid, transparent blisters and brown crusts on her chest and upper extremities. Application of a shear force to normal skin causes sloughing. Which of the following is the most likely underlying cause of this patient's condition?? 
  {'A': 'Type IV hypersensitivity reaction', 'B': 'Exfoliative toxin A release', 'C': 'Streptococcus pyogenes infection', 'D': 'Uroporphyrin accumulation', 'E': 'Anti-hemidesmosome antibody formation'},