Which two statements about the various implementations of STP are true？（）

• A、mon Spanning Tree maintains a separate spanning-tree instance for each VLAN configured in the network.
• B、The Spanning Tree Protocol （STP） is an evolution of the IEEE 802.1w standard.
• C、Per-VLAN Spanning Tree （PVST） supports 802.1Q trunking.
• D、Per-VLAN Spanning Tree Plus（PVST+） is an enhancement to 802.1Q specification and is supported only on Cisco devices.
• E、Rapid Spanning Tree Protocol （RSTP） includes features equivalent to Cisco PortFast， UplinkFast， and BackboneFast for faster network reconvergence.
• F、Multiple Spanning Tree （MST） assumes one spanning-tree instance for the entire Layer 2 network， regardless of the multiple number of VLANs