Consider the gbn protocol with a sender window size of 3 and asequence number range of 1024. suppose that a time t, the next inorder packet that the receiver is expecting has a sequencenumber of k. assume that the medium does not reorder messages. answer the foll. questions: a) what are the possible sets of sequence numbers inside thesender's window at time t? justify your answer. b) what are all the possible values of ack field in all possiblemessages currently propagating back to the sender at time t? justify your answer.