The root bridge is using a bridge priority of 4k. The exhibit shows the Root ID as 4096.00:19:e2:55:36:1e, where the first part (4096) represents the bridge priority. In STP and RSTP, the bridge priority is often displayed in hexadecimal but converts to a numerical value. Here, a priority of 4096 confirms the root bridge's bridge priority is 4k, which is 4096 in decimal.