How should a high-availability pair of Cisco Secure Firewall Threat Defense Virtual appliances be deployed...

Configure high availability first, then add only the primary Cisco Secure Firewall Threat Defense Virtual appliance to Cisco Secure Firewall Management Center.

Add the primary and secondary Cisco Secure Firewall Threat Defense Virtual appliances to Cisco Secure Firewall Management Center first, then configure high availability.

Add the primary appliance to Cisco Secure Firewall Management Center first, then configure high availability.

Configure high availability first, then add the primary and secondary appliances to Cisco Secure Firewall Management Center.