General exam question G8C10

WhyForward error correction allows the receiver to correct data errors by transmitting redundant information with the data. Forward error correction works by transmitting extra, redundant information alongside the actual data, so the receiver can use that redundancy to detect and correct errors on its own without needing to ask for a retransmission, answer C. It isn't achieved by adjusting transmit power, isn't specific to the Varicode character set, and a single parity bit per character is a much simpler error-detection technique, not the general FEC mechanism being described, so A, B, and D are wrong.