In a particular IPS protection in R71 in the Logging Settings, what does the Capture Packets option do?

In a particular IPS protection in R71 in the Logging Settings, what does the Capture Packets option do?

A.
This is not a valid selection in R71

B.
Attaches a packet capture of the traffic that matches this particular protection to each log that the protection generates.

C.
Starts a packet capture at the time of policy install to capture all of the traffic until this protection is hit.

D.
Collects all of the logs for packets that have matched this protection within the last 30 days