Complete this sentence: Spanning tree protocol… a. … reduces a partial mesh switched network in a loop free hierarchical one b. … is used by routers to route traffic between different VLANs c. …...

… reduces a partial mesh switched network in a loop free hierarchical one

… is used by routers to route traffic between different VLANs

… inserts a TTL counter into the frame headers

… reduces a partial mesh to a tree by temporarily shutting down unnecessary devices