This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Imaging of Alveolar Lung Disease, Subject name: Radiology
[{'content': 'Air bronchogram sign is seen in? \nSelect and explain. \nA. Lung abscess, B. Consolidation, C. Cavity, D. Pneumothorax', 'role': 'user'}, {'content': 'Answer: B \nExplanation: ANSWER: (B) ConsolidationREF: Grainger 4th e p. 311, Wolfgang 5th e p. 421, chapman 4th e p. 124,142Air bronchogram is a reliable sign of intrapulmonary pathology for which consolidation is most common cause.Causes of Air BronchogramInfective* PneumoniaInflammatory* Radiation pneumonitis* Progressive massive fibrosis* Edema* Fat embolismNeoplastic* Alveolar ca* Lymphoma* Lympho sarcoma* Metastasis* Kaposi sarcomaBlood in lungs* Infarction* Contusion* DIC* anticoagulants', 'role': 'assistant'}]