What is meant by a cumulative acknowledgment, ACK$(n)?1\mathrm{.}65$ points A cumulative ACK$(n)$ allows the receiver to let the sender know that it has not yet received an ACK for packet with sequence number $n.$ A cumulative ACK$(n)$ allows the receiver to let the sender know that it has not received any packets with a new sequence number since the last cumulative ACK$(n)$ was sent. A cumulative ACK$(n)$ acks all packets with a sequence number up to and including $n$ as being received.