Which of the following is a correct indication for operation on duodenal ulcer?

A. Immediate surgery should be made in all suspected acute perforation cases.

B. Pyloric obstruction must be surgically managed.

C. Surgical management is needed in case two courses of medical treatment fails.

D. The patient has a long history，frequent episodes，serious symptoms，ineffective medical management， and inability of normal work and living.

E. None of the above.