Which of the following standards is an IEEE standard that is to replace Rapid PVST+?

A. 802.1x
B. 802.1w
C. 802.1d
D. 802.1s

D. 802.1s, which is called Multiple Spanning Tree (MST), is a standard based upon PVST+. It is an open standard created by the IEEE that will allow Per-VLAN Spanning Tree in multi-vendor switched networks. However, it is not fully supported on all Cisco platforms as of yet.