A 56-year-old female presents at the emergency department after a sudden-onset middle and upper abdominal pain for 12 hours，and was diagnosed of acute pancreatitis after examination. Which of the following statements is FALSE about acute pancreatitis?

A. About 50% are secondary to bile duct diseases.

B. Bacterial infection is not a major cause of onset.

C. Further diagnostic evidence is needed if hematuria amylase is not high.

D. Sudden death is possible in certain types.

E. Residual pancreatic pseudocyst is possible.