Refer to the exhibit.

A is correct because the error message "The CRL is not accessible" indicates that the root FortiGate cannot access the CRL for the FortiClient EMS server. Verifying that the CRL is accessible will fix this error.

D is correct because the error message "The FortiClient EMS server is not authorized" indicates that the root FortiGate is not authorized to connect to the FortiClient EMS server. Authorizing the root FortiGate on the FortiClient EMS server will fix this error.

The other options are incorrect. Option B is incorrect because exporting and importing the FortiClient EMS server certificate to the root FortiGate will not fix the CRL error. Option C is incorrect because installing a new known CA on the Win2K16-EMS server will not fix the authorization error.

References:

Troubleshooting FortiClient EMS connectivity | FortiClient / FortiOS 7.0.0 - Fortinet Document Library

Authorizing FortiGates with FortiClient EMS | FortiClient / FortiOS 6.4.8 - Fortinet Document Library

https://docs.fortinet.com/document/fortigate/7.0.0/administration-guide/185333/forticlient-ems%E2%80%9D