This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pleural effusion & Pulmonary alveolar proteinosis, Subject name: Medicine
[{'content': 'Bronchoalveloar lavage is beneficial in the evaluation of: \nSelect and explain. \nA. Squamous cell cancer lung, B. Bronchiectasis, C. Bronchopleural fistula, D. Pulmonary alveolar Proteinosis', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Pulmonary alveolar proteinosis can be diagnosed by Bronchoscopy with transbronchial biopsy and BAL may be helpful. Bronchoalveolar lavage fluid appears "milky". Papanicolaou staining may reveal green and orange globules that are diagnostic for PAP. Electron microscopy of BAL may reveal characteristic multi-lamellar structures. Non small cell cancer lung is diagnosed by bronchoscopy with biopsy Bronchiectasis is diagnosed with HRCT scan Bronchopleural fistula is diagnosed with bronchoscopy and is usually a complication of lung cancer surgery', 'role': 'assistant'}]