This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Anatomy
[{'content': 'Cause of central cyanosis include all the following except \nSelect and explain. \nA. Chronic asthma, B. Congestive pulmonary stenosis, C. Congestive hea failure, D. Alveolar hypotension', 'role': 'user'}, {'content': 'Answer: C \nExplanation: CHF is a cause for peripheral cyanosis and not central cyanosis. Cyanosis when present in asthma,pulmonic stenosis and alveolar hypoventilation is of central type. Ref Harrison 19th edition pg 249', 'role': 'assistant'}]