This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Obstructive Lung Diseases, Subject name: Pathology
All are obstructive lung disease except - 
Select and explain. 
A. Emphysema, B. Interstitial fibrosis, C. Asthma, D. Bronchitis
B: Interstitial fibrosis
Answer: B: Interstitial fibrosis 
Explanation: 11Ans. is 'b' i.e., Interstitial fibrosis Diffuse pulmonary diseases are divided into two categories -Obstructive disease (airway disease)o 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,o Examples are chronic obstructive lung disease (COPD - Emphysema, bronchitis), bronchiectasis, and asthma.Restrictive diseaseo Restrictive disease is characterized by reduced expansion of lung parenchyma, with decreased total lung capacity,o It may occur due to two types of disorders -Chest wall disorders in the presence of Normal lungs - Neuromuscular disorders, e.g.polio, severe obesity, pleural disease, kyphoscoliosis.Interstitial and infiltrative diseases of lung - Pneumoconiosis, interstitial fibrosis.