Answer:
Refer to explaination
Step-by-step explanation:
A NAK only protocol is not preferable to a protocol that uses ACKs especially when the sender sends data frequently.
This is because NAK only protocol will be able to detect that a packet has been lost already when the receiver receives the subsequent packet. Also, as the sender only sends data infrequently, NAK only protocol takes a longer time to realize that a packet has been lost.
On the other hand, NAK only protocol is preferred to a protocol that uses ACKs, when the sender sends data out frequently, here the data loss rate is low.