What is happening when a BGP session is stuck in the $$Active$$ state?a$.$ The router is listening for an inbound TCP connection attempt from the remote peer but it is not able to respond properly.b$.$ The router is attempting to establish an outbound TCP connection with the remote peer but is not receiving the expected response.c$.$ An Open message has been transmitted to the remote peer but the expected response message has not been received from the peer.d$.$ A Keep$-$Alive message has been transmitted to the remote peer but the expected response message has not been received from the peer.