Suppose that you ping another computer on the network to test the network and you receive no response other than timeouts. The target computer is running on a different subnet from the computer you pinged from. The network cable is plugged in$,$ and no firewall is running inside the network. Moreover, the target computer responds to pings from other computers in the same subnet, but it cannot be pinged by any computer in a different subnet. Which of the following is the most likely cause of this problem?