What is the prefix length of a class A IPv4 address?

The prefix length of a class A IPv4 address is /8. In an IPv4 address, the prefix length indicates how many bits are used for the network portion of the address. Class A addresses start with a binary '0', which means the first octet can range from 0 to 127. The first 8 bits (or 1 octet) in a Class A address represent the network part, leaving the remaining 24 bits for host addresses within that network. This structure provides a significant number of host addresses under a single network, allowing for large organizations to operate their networks with a wide range of device addresses.

The other options represent prefix lengths that correspond to different classes of IPv4 addresses. Class B addresses have a prefix length of /16, allowing for fewer hosts than Class A, and Class C addresses have a prefix length of /24, enabling an even smaller number of hosts. The /32 prefix length signifies a specific address assigned to a single host, indicating that there are no remaining bits for additional devices within that address space.