Which of the following is a valid IPv4 address?

Correct option is D

The IPv4 address 192.168.1.1 is a valid address because each octet (separated by dots) is a number between 0 and 255, which meets the criteria for a valid IPv4 address.
Important Key Points:
1. Valid IPv4 Address: A valid IPv4 address consists of four octets, where each octet is a number between 0 and 255. For example, 192.168.1.1 meets these requirements.
2. Range of Each Octet: Each octet in an IPv4 address can only contain values from 0 to 255, as any number greater than 255 is not valid in this context.
3. Private Address: 192.168.1.1 is commonly used as a default private IP address in local networks, often as the gateway address in home routers.