Which two statements are true about the primary address on an interface?（）

• A、It is the address used by default as the local address for broadcast and multicast packets sourced locally and sent out of the interface.
• B、You use the primary address when you have multiple IP addresses belonging to the same subnet on the same interface.
• C、It can be useful for selecting the local address used for packets sent out of unnumbered interfaces when multiple non-127 addresses are configured on the loopback interface.
• D、By default, the primary address on an interface is selected as the numerically highest local address configured on the interface.