You are answering a USMLE-style medical question. Question: A 6-year-old boy is brought to the emergency department by his mother for worsening wheezing and shortness of breath over the past day. He has not had a fever, cough, vomiting, or diarrhea. He has asthma and eczema. He uses a glucocorticoid inhaler and an albuterol inhaler but has missed his medications for the past week while on vacation. He appears uncomfortable. His temperature is 36°C (96.8°F), pulse is 120/min, respirations are 40/min, and blood pressure is 100/80. Expiratory and inspiratory wheezing is heard throughout both lung fields. There are moderate intercostal and subcostal retractions and a decreased inspiratory to expiratory ratio. Nebulized albuterol and ipratropium treatments and intravenous methylprednisolone are given in the emergency department for a presumed asthma exacerbation. One hour later, the child is limp and lethargic. Magnesium sulfate is administered. His temperature is 36°C (96.8°F), pulse is 150/min, respirations are 22/min, and blood pressure is 100/70. No wheezing is heard on repeat pulmonary examination. Which of the following is the most appropriate next step in management? Options: A) Intubate with mechanical ventilation B) Perform needle thoracostomy at the 2nd intercostal space C) Perform bronchoscopy D) Provide additional dose of methylprednisolone Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.