IPv4 addresses consist of four octets, each ranging from 0 to 255. The addresses are used to uniquely identify devices on a network. A . 255.255.255.255 is reserved for broadcast messages to all hosts on the local network, so it cannot be assigned to a single host. B . 10.1.1.20 falls within the range of private IP addresses (10.0.0.0 to 10.255.255.255) and can be assigned to a host within a private network. C . 0.0.0.0 is used to denote an unknown or non-applicable target address, often used as a default route, and cannot be assigned to a host. D . 192.168.10.15 is also within the range of private IP addresses (192.168.0.0 to 192.168.255.255) and can be assigned to a host within a private network. E . 292.10.3.4 is not a valid IPv4 address because the first octet exceeds the maximum value of 255. Reference: IPv4 Addressing Valid IP Address IP Address Validation