Special polynomial codes provide automatic correction
If errors are detected, redundant data is substituted
If errors are detected, a retransmission is requested✓الإجابة الصحيحة
الشرح
ARQ stands for automatic repeat request: the receiver checks each block, and when the check fails it uses the return path to ask the sender to transmit that block again. Reconstructing the data from redundancy carried within the transmission, with no return path, is forward error correction — a different technique.