Final answer:
The IPv6 prefix reserved for communication between devices on the same link is Link-Local, which is used exclusively within a local network and is non-routable.
Step-by-step explanation:
The IPv6 prefix that is reserved for communication between devices on the same link is a) Link-Local.
Link-local addresses are used for communication between devices on the same local network. These addresses are not routable, which means they cannot be used to communicate with devices outside of the local network link. In contrast, Global addresses are used on the wider internet, Site-local was a concept deprecated in favor of Unique-Local addresses, which are used for local communications within a site or organization without the need for a global prefix.