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: Medicine
[{'content': 'Bibasilar Velcro crackles occur in ? \nSelect and explain. \nA. Acute pulmonary oedema, B. Acute bronchopneumonia, C. Pulmonary fibrosis, D. Pulmonary embolism', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]