Change Password

You have an IP address of 172.16.13.5 with a 255.255.255.128 subnet mask. What is your class of address, subnet address, and broadcast address ?
Class A, Subnet 172.16.13.0, Broadcast address 172.16.13.127
Class B, Subnet 172.16.13.0, Broadcast address 172.16.13.127
Class B, Subnet 172.16.13.0, Broadcast address 172.16.13.255
Class B, Subnet 172.16.0.0, Broadcast address 172.16.255.255