What can be the reason for this failure?

The admin administrator is failing to register a FortiClient EMS on the FortiAnalyzer device.

What can be the reason for this failure?
A . FortiAnalyzer is in an HA cluster.
B. ADOM mode should be set to advanced, in order to register the FortiClient EMS device.
C. ADOMs are not enabled on FortiAnalyzer.
D. A separate license is required on FortiAnalyzer in order to register the FortiClient EMS device.

Answer: C

Explanation:

Reference: https://help.fortinet.com/fa/faz50hlp/56/5-6-2/FMG-FAZ/0800_ADOMs/0015_FortiClient%20and%20ADOMs.htm