A domain user is able to successfully log into the vSphere Web Client, but notices that the vCenter Server
system does not appear in the inventory.
Which is the cause of this situation?

A.
The Service Control Agent service is not running.

B.
The vCenter Server does not have any hosts added to inventory yet.

C.
The domain user has read-only permissions on vCenter Server.

D.
The domain user does not have vCenter Server permissions.

Explanation:
https://pubs.vmware.com/vsphere-51/index.jsp?topic=%
2Fcom.vmware.vsphere.troubleshooting.doc%2FGUID-B7662658-9C2C-4C6E-809B-F211B1B08157.html