This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': 'All of the following statements regarding theophylline are true except: \nSelect and explain. \nA. Increases cAMP, B. Inhibits phosphodiesterase, C. Increase in dose is required in smokers, D. Increase in dose is required in cardiopulmonary disease', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Theophylline is a methylxanthine , used in the treatment of bronchial asthma. Its dose has to be reduced in elderly (age > 60years), in congestive hea failure, pneumonia and liver failure. Ref: Essentials of Medical Pharmacology, 5th Edition, Page 203', 'role': 'assistant'}]