Which Action Does the Router Take as It Forwards a Packet

Which action does the router take as it forwards a packet through the network?

A) The router encapsulates the original packet and then includes a tag that identifies the source router MAC address and transmits it transparently to the destination.
B) The router encapsulates the source and destination IP addresses with the sending router IP address as the source and the neighbor IP address as the destination.
C) The router replaces the original source and destination MAC addresses with the sending router MAC address as the source and neighbor MAC address as the destination.
D) The router replaces the source and destination labels with the sending router interface label as a source and the next hop router label as a destination.