An engineer is configuring switch SW1 to act as an NTP server when all upstream NTP server connectivity fails. Which configuration must be used?
A. SW1# config t
SW1(config)#ntp peer 192.168.1.1
SW1(config)#ntp access-group peer accesslist1
B. SW1# config t
SW1(config)#ntp master
SW1(config)#ntp server192.168.1.1
C. SW1# config t
SW1(config)#ntp backup
SW1(config)#ntp server192.168.1.1
D. SW1# config t
SW1(config)#ntp server192.168.1.1
SW1(config)#ntp access-group peer accesslist1
A. SW1# config t
SW1(config)#ntp peer 192.168.1.1
SW1(config)#ntp access-group peer accesslist1
B. SW1# config t
SW1(config)#ntp master
SW1(config)#ntp server192.168.1.1
C. SW1# config t
SW1(config)#ntp backup
SW1(config)#ntp server192.168.1.1
D. SW1# config t
SW1(config)#ntp server192.168.1.1
SW1(config)#ntp access-group peer accesslist1