Which three items are configured in MST configuration submode? (Select three)

A.
Region name

B.
Configuration revision number

C.
VLAN instance map

D.
IST STP BPDU hello timer

E.
CST instance map

F.
PVST+ instance map

Explanation:
spanning-tree mst configuration:
Use the spanning-tree mst configuration command to enter the MST configuration submode.
Use the no form of this command to return to the default MST configuration.
Defaults:
The default value for the MST configuration is the default value for all its parameters:
No VLANs are mapped to any MST instance (all VLANs are mapped to the CIST instance).
The region name is an empty string.
The revision number is 0.
Usage Guidelines:
The MST configuration consists of three main parameters:

Instance VLAN mapping (see the instance command)
Region name (see the name command)
Configuration revision number (see the revision command)