单项选择题

In a physiological experiment, a medical student noticed a large amount of pancreatic secretion when the acidic chyme entered the small intestine. Which of the following mechanism could explain this phenomenon? ()

A.Vagus nerve excitement
B.Small intestine mucosa releases gastrin
C.Sympathetic excitement
D.Intestinal mucosa releases secretin
E.Acidic chyme directly stimulate pancreatic secretion