What is one benefit of PVST+?

What is one benefit of PVST+?
A . PVST+ supports Layer 3 load balancing without loops.
B . PVST+ reduces the CPU cycles for all the switches in the network.
C . PVST+ allows the root switch location to be optimized per VLA
E . PVST+ automatically selects the root bridge location, to provide optimized bandwidth usage.

Answer: C

Explanation:

Per VLAN Spanning Tree (PVST)

Introduction

http://www.cisco.com/en/US/tech/tk389/tk621/tk846/tsd_technology_support_sub-protocol_home.html

Per VLAN Spanning Tree (PVST) maintains a spanning tree instance for each VLAN configured in the network. This means a switch can be the root bridge of a VLAN while another switch can be the root bridge of other VLANs in a common topology. For example, Switch 1 can be the root bridge for Voice data while Switch 2 can be the root bridge for Video data. If designed correctly, it can optimize the network traffic.

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