3. Consider a Go-Back-N protocol with a sender window size of 5 and a sequence number range of 1,024, and assume the receiver sends ACKs with the number of the next sequence number expected. Suppose that at time t, the next in-order packet that the receiver is expecting is a packet with the sequence number 8. Assume that the channel does not reorder packets. (a) What are the possible sets of sequence numbers inside the sender's window at time f? Justify your answer (b) What are all possible values of the ACK field in all possible messages currently propagating back to the sender at time t? Justify your