Which statements are true about system ID?

On Cisco Nexus 7000 Series Switch Cisco FabricPath domain, one switch becomes the root for
the multidestination tree. Cisco FabricPath IS-IS will automatically select root switches for each
multidestination tree. One of the parameters used to select the root is system ID.
Which statements are true about system ID? (Choose two.)

A.
System ID is a unique 12-bit SID.

B.
System ID is a 48-bit value composed of the VDC MAC address.

C.
Higher system ID is preferred.

D.
Lower system ID is preferred.

Explanation: