The prefix associated with the IPv6 address 1/64 is C) /64, indicating that the first 64 bits are used for the network portion of the address.
The prefix associated with the IPv6 address 1/64 is C) /64. In IPv6 addressing, the prefix length is specified after the slash, which indicates how many bits are used for the network portion of the address. A /64 prefix length means that the first 64 bits of the IPv6 address are the network part, and the remaining bits are available for host addresses. This is a common subnet size for IPv6 networks, providing a very large number of host addresses.