On a Chest X-ray, if 'air bronchogram' is seen within the opacity, means opacity is?

Ans. C. Intrapulmonary. (Ref. Sutton 7th/pg. 26)Air bronchogram sign: Parenchymal lung consolidation may result in visualization of the intrapulmonary bronchi, whichare otherwise not visible on normal chest radiograph, because the air within their lumens will then stand out in contrastto the surrounding opaque lung, known as air bronchogram.Various causes of air bronchogram sign are:1) Normal person with phase of long exposure2) Consolidation3) Atelectasis (except in obstructive type)4) Alveolar cell carcinoma5) Pulmonary alveolar microlithiasis6) Pulmonary edema7) Pulmonary infarction (temporary)8) Pulmonary lymphoma of alveolar type9) Pulmonary hemorrhage10) Aspiration11) Sarcoidosis