This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Radiology
X-ray features of ASD are all except - 
Select and explain. 
A. Right atrial enlargement, B. Left atrial enlargement, C. Pulmonary plethora, D. Small aoic knockle
B: Left atrial enlargement
Answer: B: Left atrial enlargement 
Explanation: Characteristic features of ASD include enlarged hea,Right Atrium,Right Ventricle,Pulmonary Aery and Pulmonary Vein with Normal Left atrium and Left ventricle and decreased aoa and SVC.