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: Pathology
[{'content': 'Which of the following is an obstructive lung disease - \nSelect and explain. \nA. Interstitial fibrosis, B. Obesity, C. Emphysema, D. Kyphosis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Diffuse pulmonary diseases are divided into two categories -\n1. Obstructive disease (airway disease)\nThe obstructive disease is characterized by an increase in resistance to airflow owing to partial or complete obstruction at any level, from the trachea to the respiratory bronchioles.\nExamples are chronic obstructive lung disease (COPD - Emphysema, bronchitis), bronchiectasis, and asthma.\n2. Restrictive disease\nThe restrictive disease is characterized by reduced expansion of lung parenchyma, with decreased total lung capacity.\nIt may occur due to two types of disorders -\n(i)\xa0Chest wall disorders in the presence of Normal lungs →\xa0Neuromuscular disorders, e.g. polio, severe obesity, pleural disease, kyphoscoliosis.\n(ii)\xa0Interstitial and infiltrative diseases of lung → Pneumoconiosis, interstitial fibrosis.', 'role': 'assistant'}]