Comprehensive Explanation: In STP (Spanning Tree Protocol), the root bridge is elected based on the lowest Bridge ID. The Bridge ID consists of two parts: the bridge priority and the MAC address of the switch. The switch with the lowest Bridge ID is elected as the root bridge. If two switches have the same priority, the switch with the lowest MAC address becomes the root. Other parameters such as Port ID and Root path cost are used in subsequent decisions to determine the best paths to the root bridge, but they are not used in the root bridge election itself.
