Two communication nodes use the Go$-$Back$-$N ARQ protocol

with a window size of $500.$ Frames $1$ to $500$ are sent, but frame $500$

is received in error. In this case the transmitter needs to:

$($a$)$ retransmit frame $500$ only $($b$)$ retransmit frame $1$ and all

subsequent frames $($c$)$ retransmit frames $1$ to $500($d$)$ neither a$,$ b

or c$.$