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
Most impoant pathophysiological cause of GERD is: 
Select and explain. 
A. Hiatus hernia, B. Transient LES relaxation, C. Hypotensive LES, D. Intermittent changes in LES pressure tone
B: Transient LES relaxation
Answer: B: Transient LES relaxation 
Explanation: Ans. b. Transient LES relaxation