Consider a client and a server application communicating over TCP$.$ In what follows, we

consider the socket opened by the client application to communicate to the server, and the

connected socket $($not a listening socket$)$ at the server application to communicate to this client.

If no errors have occurred in the operation of either TCP endpoint, and no packets have been lost

by the intervening network, is it possible for the two TCP endpoints to be in the following

combination of states? Answer separately for each combination; each part is independent of

others.

$($a$)$ Client endpoint is ESTABLISHED, server endpoint is in the SYN$\_$RCVD$.$

$($b$)$ Client endpoint is FIN$\_$WAIT$\_1,$ server endpoint is in the SYN$\_$RCVD$.$

$($c$)$ Client endpoint is SYN$\_$SENT, server endpoint is FIN$\_$WAIT$\_1.$