For option a) and b), the following argument holds.
Suppose sender sends a window and the receiver successfully recieves it. Now, the receiver will send ACK but due to delay these acknowledgement haven't reached sender so far. The sender timesout and resends these packets but the receiver window has already moved ahead because of previous packets. The receiver will resend ACK signifying duplicate packets. These ACK reach the sender and the sender window moves ahead. Now, if the ACK that were earlier delayed also arrive then these ACKs are outside of the sender window.
For option c) and d), I am assuming they mean Stop and Wait, in which case it is pretty clear from the window sizes that the restrictions of window size = 1 on both GBN and SR makes them Stop and Wait essentially.
