You Want to Configure Redundant Layer 3 Gateways

You want to configure redundant Layer 3 gateways. In this scenario, which two Juniper best practices would accomplish this task? (Choose two.)

A) configuring both IRB interfaces manually with the same MAC address.
B) allowing Junos to dynamically create the virtual IP address of the IRB interface.
C) configuring both IRB interfaces manually with the same IP address.
D) allowing Junos to dynamically create the virtual MAC address of the IRB interface.