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
Which of the following is false about ambulatory pH monitoring 
Select and explain. 
A. H2 blocking agents must be stopped before 3 days, B. PPI must be stopped before 14 days, C. Sensitivity and specificity is 70%, D. It is done before antireflux surgery
C: Sensitivity and specificity is 70%
Answer: C: Sensitivity and specificity is 70% 
Explanation: It has a sensitivity and specificity of 92%