Transmitting redundant information with each character or frame to facilitate detection and correction of errors
is called a:

A.
feedback error control.

B.
block sum check.

C.
forward error control.

D.
cyclic redundancy check.

Explanation:
Forward error control involves transmitting additional redundant information with each character or frame to
facilitate detection and correction of errors, in feedback error control, only enough additional information is
transmitted so the receiver can identify that an error has occurred. Choices B and D are both error detection
methods but not error correction methods. Block sum check is an extension of parity check wherein an
additional set of parity bits is computed for a block of characters. A cyclic redundancy check is a technique
wherein a single set of check digits is generated, based on the contents of the frame, for each frame
transmitted.