What is a key feature of Generic Routing Encapsulation $($GRE$)$ in the context of IPV$4$ and IPv$6$ transition mechanisms?

GRE allows only IPv$6$ packets to be encapsulated within IPv$4$ packets.

GRE requires manual configuration of each packet's destination address.

GRE enables the encapsulation of a wide variety of Network layer protocols within virtual point$-$to$-$point links.

GRE is exclusively used for IPv$6$ to IPv$4$ address translation.