The correct answer is œoption 1.CONCEPT:Original timestamp: Original timestamp is the time at which the sender sent the packet.Receiving timestamp: Receiving timestamp is the time at which the receiver receives the packet.Transmit Timestamp: Transmit timestamp is the timestamp at which the receiver of the message sent the reply packet.Returned timestamp: Returned timestamp is the timestamp at which the sender of the message receives the reply packet.Formulas related to timestamp are:Sending time = Receiving time “ Original timeReceiving time = Returned time “ transmit timeRound trip time = sending time + receiving timeOne-way time = \(\frac{RTT}{2}\)CALCULATION:Original timestamp: 46Receiving timestamp: 59Transmit timestamp: 60Returned timestamp: 67Sending time = 59ms - 46ms= 13 msReceiving time = 67 ms - 60 ms= 7 msRTT = 13 ms + 7 ms= 20 msOne-way time = \(\frac{20}{2}\)= 10 msTime difference = Receive timestamp “ (original timestamp + one-way time)= 59 ms - (46 ms + 10 ms)= 59 - 56= 3 msHence, the receiver should go back by 3 ms.