John is a network technician of his company. He is informed that the email server (192.168.1.10) will be restarted in five minutes for maintenance. Which command can help him determine when the system comes back online in real-time?

A.
ping a 192.168.1.10

B.
tracert 192.168.1.10

C.
ping t 192.168.1.10

D.
tracert d 192.168.1.10