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: Surgery
The commonest cause of metabolic alkalosis is - 
Select and explain. 
A. Cancer stomach, B. Pyloric stenosis, C. Small-bowel obstruction, D. Diuretics
B: Pyloric stenosis
Answer: B: Pyloric stenosis 
Explanation: None