Which of these options will prevent a device from being able to initiate conferences?

Which of these options will prevent a device from being able to initiate conferences?

A.
Exclude the conference media resource partitions from the CSS.

B.
Exclude the conference media resources from all MRGs.

C.
Place all conference media resources in MRGs and exclude these MRGs from the MRGL.

D.
Remove the default MRGL from the device pool.