2.R1 router clock is synchronized with ISP router. R2 is supposed to receive NTPupdates from Rl. But you observe that R2 clock is not synchronized with Rl. What isthe reason R2 is not receiving NTP updates from Rl?A. Rl router Ethernet interface that is connected to R2 is placed in shutdowncondition.B. R2 router Ethernet interface that is connected to Rl is placed in shutdowncondition.C.The NTP server command not configured on R2 router.D.The IP address that is used in the NTP configuration on R2 router is incorrect.