Which two descriptions of the HomeNet and ExternalNet variable sets that are used within Cisco Firepower access control and IPS policies are true?

Which two descriptions of the HomeNet and ExternalNet variable sets that are used within Cisco Firepower access control and IPS policies are true?(Choose two)
A. They are used exclude or include protected network subnets from security intelligence and blacklist filtering
B. They are used to decrease the number of false positives by defining the protected network
C. They are used to fine tune the performance of the appliance by optimizing how signatures are matched to packets based on the source and destination addresses in packet
D. They are used for reporting reasons to give context on the direction of a connection or malicious attack as it appears in the event viewer and reports
E. They are a legacy snort feature that has no effect since Firepower 6.x