Which classification rule is only possible using the Veritas Information Classifier as the classification method?

Which classification rule is only possible using the Veritas Information Classifier as the classification method?
A . a rule for items that contain the words “insider” and “trading” within 50 characters of each other
B . a rule for items that contain the word “fraud” in the content, but not in the subject
C . a rule for items that were sent with high importance
D . a rule for items that contain exactly one BCC recipient

Answer: A