TImagine a network with two routers that are connected with a point$-$to$-$point HDLC serial link. Each router has an Ethernet, with PC$1$ sharing the Ethernet with Router$1$ and PC$2$ sharing the Ethernet with Router$2.$ When PC$1$ sends data to PC$2,$ which of the following is true?

Router$1$ strips the Ethernet header and trailer off the frame received from PC$1,$ never to be used again.

Router$1$ encapsulates the Ethernet frame inside an HDLC header and sends the frame to Router$2,$ which extracts the Ethernet frame for forwarding to PC$2.$

Router$1$ strips the Ethernet header and trailer off the frame received from PC$1,$ which is exactly re$-$created by Router$2$ before forwarding data to PC$2.$

Router$1$ removes the Ethernet, IP$,$ and TCP headers and rebuilds the appropriate headers before forwarding the packet to Router$2.$