Which of the following is true about Negative ACK in Error Control mechanism?

As soon as the receiver receives a correct frame, it should acknowledge it.

In this, the sender and receiver either both or any, must ascertain that there’s been some error on transit.

In case, the receiver receives a duplicate frame, it sends a NACK back to the sender and the sender must retransmit the correct frame.

The sender checks the acknowledgement of a data-frame previously transmitted does not arrive in the timeout period, the sender retransmit the frame.

None of the above