Consider the sliding window protocol used at transport layer to transfer the segments, the receiver sends “ACK K + 1” when it receives a packet with sequence number “K” and window size is denoted by “W”. Assume the sender’s packets start with sequence number 1. Which of the following is correct about sliding window protocol?
(A) Between two ACK packets, the sender will never send more than one packet
(B) The sender must retransmit any packets for every single duplicate ACK it receives.
(C) Any new (previously unsent) packet with sequence number greater than “W” is sent by sender iff a new (previously unseen) ACK arrives.
(D) None of the above