How does Layer 3 VPN traffic traverse an ISP network?

Devices on the network use MPLS labels to share VPN routes between P routers in the network.

Devices on the network use LSAs to share routes between P routers in the network.

Devices on the network use MPLS labels to move VPN traffic through the network.

Devices on the network use GRE tunnels to move traffic between VRFs.