In the Stop-and-Wait ARQ protocol, acknowledgements are sent by the receiver for each data packet it successfully receives. - For every data packet sent and received, a corresponding acknowledgement is generated. - If 10 data packets are sent and successfully received, the receiver will generate 10 acknowledgements. - The option '11' suggests an additional acknowledgement is needed, often related to connection termination (e.g., acknowledging a FIN packet after data transfer is complete). If the question implies the entire sequence including termination, then 11 is plausible.