Refer to the exhibit.

Which statement is true about the IPS signature shown?

A.
To match a string, the regular expression requires zero or more period characters (.) to immediately precede the newline character.

B.
A summary alert is sent once during each interval for each unique Summary Key entry.

C.
An alert is generated each time the signature triggers.

D.
This signature does not fire until three events are seen during 60 minutes with the same attacker and victim IP addresses and ports.

E.
This signature does not analyze traffic that is sent from the SMTP server to the client.