Which router command will configure an interface with the IP address 10.10.80.1/19?

Which router command will configure an interface with the IP address 10.10.80.1/19?
A . router(config-if)# ip address 10.10.80.1/19
B . router(config-if)# ip address 10.10.80.1 255.255.0.0
C . router(config-if)# ip address 10.10.80.1 255.255.255.0
D . router(config-if)# ip address 10.10.80.1 255.255.224.0
E . router(config-if)# ip address 10.10.80.1 255.255.240.0
F . router(config-if)# ip address 10.10.80.1 255.255.255.240

Answer: D

Explanation: