Computer Science for IGCSE & O level - Data Transmission (Section 5 - No. 23)

Which of the following best describes the operation of an echo check?

The sender sends a copy of the data and the receiver compares to the original to detect the error.

The receiver sends a copy of the data back to the sender to verify it.

The sender encrypts the data, and the receiver decrypts it to verify data.

It is a part of checksum and parity check methods.

In an echo check, the receiver returns the received data to the sender to verify its integrity.