Consider the Go-back N scheme with window size N = 2 and assume that 2 bits are used for the sequence number field. The sender has four packets (labeled A, B, C and D) to send to the receiver. Suppose that packet C is lost the first time that the sender tries to transmit it. Other than this event, all other packets are transmitted successfully over the channel. Draw two parallel timelines showing the sequence of events that at occur at the sender and receiver, respectively, beginning with the transmission of packet A and ending with the successful reception of packets A through D. Show the state of the sender's window (i.e., indicate ‘base' and ‘nextseqnum') after each event at the sender, assuming that initially