This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Surgery
The gold standard for diagnosing acid reflux is 
Select and explain. 
A. Endoscopy, B. 24-hour pH monitoring, C. Manometry, D. Esophagogram
B: 24-hour pH monitoring
Answer: B: 24-hour pH monitoring 
Explanation: The gold standard for diagnosing and quantifying acid reflux is the 24-hour pH test.Sabiston 20th edition Pg: 1070