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: Radiology
Air bronchogram on chest Xray denotes 
Select and explain. 
A. Intrapulmonary lesion, B. Extrapulmonary lesion, C. Intrathoracic lesion, D. Extrathoracic lesion
A: Intrapulmonary lesion
Answer: A: Intrapulmonary lesion 
Explanation: A solitary pulmonary nodule (SPN) or coin lesion is a mass in the lung smaller than 3 centimeters in diameter.
It can be an incidental finding found in up to 0.2% of chest X-rays and around 1% of CT scans.