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
X-ray feature of pyloric stenosis is: March 2013 (c) 
Select and explain. 
A. Single bubble appearance, B. Double bubble appearance, C. Triple bubble appearance, D. Multiple bubble appearance
A: Single bubble appearance
Answer: A: Single bubble appearance 
Explanation: Ans. A i.e. Single bubble appearance