What is the range of valid stratum numbers for NTP when configuring a Cisco IOS device
as an authoritative NTP server?
A.
0 to 16
B.
1 to 15
C.
0 to 4
D.
1 to 16
Explanation:
When configuring a Cisco device as NTP master its clock becomes a reference clock for
time synchronization to other devices. The stratum of the NTP master can be configured
in the range 1-15, but will usually be configured as stratum-1
https://seriousnetworks.wordpress.com/2013/08/08/configuring-ntp-oncisco-ios-devices/