Which term is described as 'send back to confirm'?

Which term is described as 'send back to confirm'?

• A. Echo check
• B. Check digit
• C. Automatic repeat query
• D. Checksum

Answer: (D)

Data integrity verification using a checksum. A checksum is a value derived from the data and sent with it; the receiver recalculates the checksum from what arrives and compares it to the transmitted value. If they match, the data is considered intact, which is effectively a signal that the data has been confirmed as unaltered in transit. That’s why it fits the description of “send back to confirm”—the checksum provides a compact proof that the transmission is correct. The other terms point to related but different ideas: an echo-style response would simply repeat data to confirm receipt, a check digit is a single digit used to catch simple errors in identifiers, and an automatic repeat query is a mechanism to request retransmission after errors.

Data integrity verification using a checksum. A checksum is a value derived from the data and sent with it; the receiver recalculates the checksum from what arrives and compares it to the transmitted value. If they match, the data is considered intact, which is effectively a signal that the data has been confirmed as unaltered in transit. That’s why it fits the description of “send back to confirm”—the checksum provides a compact proof that the transmission is correct. The other terms point to related but different ideas: an echo-style response would simply repeat data to confirm receipt, a check digit is a single digit used to catch simple errors in identifiers, and an automatic repeat query is a mechanism to request retransmission after errors.