Which of the Following Best Defines an Outbreak

Which of the following best defines an outbreak?

A) The diagnosis of several cases of disease in the same geographic region
B) The diagnosis of several cases in the same week
C) The number of cases observed in an area is twice that normally reported in the same time period
D) The number of cases observed in an area is ten times that normally reported in the same time period
E) The number of cases observed in an area is clearly higher than would normally be expected in the same time period