What IPv6 address block is reserved for link-local addresses?

Link-local addresses in IPv6 are utilized for communication between nodes in the same local network segment or link. They are not routable beyond that link, making them critical for operations such as neighbor discovery and automatic address configuration.

The specific block reserved for link-local addresses is FE80::/10. This means that any address that starts with the prefix FE80 through FEBF is designated for link-local use. These addresses are automatically assigned to interfaces, allowing devices on the same link to communicate without the need for configuration or a globally routable address.

The other choices represent different types of addresses. The FC00::/7 block is reserved for unique local addresses, which are somewhat analogous to private addresses in IPv4 but are intended for use within a site or organization. The 2001::/16 address block is used for global unicast addresses, allowing for Internet-wide uniqueness. Meanwhile, FF00::/8 is designated for multicast addresses, which serve to transmit data to multiple hosts simultaneously.

Therefore, the correct answer, which signifies the specific address range used for link-local addressing, is FE80::/10.