You are answering a USMLE-style medical question. Question: A 15-year-old boy with poorly controlled asthma presents to the emergency room complaining of severe shortness of breath. His mother reports that he had trouble breathing soon after he started playing soccer with some friends and was unable to use his inhaler as it was empty. His family history is notable for emphysema in his paternal uncle and cirrhosis in his maternal grandfather. The child’s temperature is 99.0°F (37.2°C), blood pressure is 130/90 mmHg, pulse is 130/min, respirations are 28/min, and oxygen saturation is 91% on room air. Physical examination demonstrates wheezing bilaterally in all lung fields. The child is started on supplemental oxygen and a nebulized bronchodilator. Which of the following is a downstream effect of this medication? Options: A) Decreased leukotriene activity B) Activation of muscarinic receptors C) Decreased phosphodiesterase activity D) Increased adenylate cyclase activity Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.