Which of the following represents a public IP address?

A public IP address is an address that is routable on the internet and is not reserved for private networks. The range of IP addresses that are designated specifically for private use includes those defined in the following blocks: 10.0.0.0 to 10.255.255.255, 172.16.0.0 to 172.31.255.255, and 192.168.0.0 to 192.168.255.255.

The address 225.16.0.5 falls into the range known as multicast addresses, which are used for sending data to multiple hosts at once, distinct from regular public or private IPs. Since it doesn't fall into the private address ranges, it is considered a public IP address.

In contrast, the other options provided (172.20.5.9, 192.168.100.100, and 10.0.6.8) are private IP addresses, as they fall within the reserved blocks specified for private use. Consequently, B is the only address listed that qualifies as a public IP address, used for communication over the internet rather than within a confined, private network.