Which statement about error-detection methods is correct?

Which statement about error-detection methods is correct?

• A. Parity detects multi-bit errors.
• B. Parity detects single-bit errors.
• C. CRC detects errors across blocks more robustly than parity.
• D. Checksums cannot detect errors.

Answer: (B)

Parity error-detection is built to catch single-bit flips. By adding a parity bit, the transmitter ensures the total number of 1s has a fixed parity (even or odd). If exactly one bit flips during transmission, that change alters the parity, and the receiver flags an error. This makes parity a simple and reliable way to detect single-bit errors. However, it cannot guarantee detection of multiple-bit errors, because an even number of flips can leave the parity unchanged and go unnoticed. So the statement that parity detects single-bit errors reflects its strongest and most dependable capability. While more advanced methods like CRC are indeed more robust in detecting a wider range of errors (including burst errors) and checksums can catch many mistakes, parity’s defining strength is detecting single-bit flips.

Parity error-detection is built to catch single-bit flips. By adding a parity bit, the transmitter ensures the total number of 1s has a fixed parity (even or odd). If exactly one bit flips during transmission, that change alters the parity, and the receiver flags an error. This makes parity a simple and reliable way to detect single-bit errors. However, it cannot guarantee detection of multiple-bit errors, because an even number of flips can leave the parity unchanged and go unnoticed. So the statement that parity detects single-bit errors reflects its strongest and most dependable capability. While more advanced methods like CRC are indeed more robust in detecting a wider range of errors (including burst errors) and checksums can catch many mistakes, parity’s defining strength is detecting single-bit flips.