How can you configure a switch to become the root of a spanning-tree?

The most effective way to configure a switch to become the root of a spanning-tree is to adjust the switch priority to a lower value. In the Spanning Tree Protocol (STP), the switch with the lowest bridge ID is elected as the root bridge. The bridge ID consists of the switch's priority and its MAC address. By lowering the priority value of the switch, you increase its chances of being elected as the root bridge.

Other options, while beneficial in certain contexts, do not directly result in the switch becoming the root of the spanning-tree. Using Rapid Spanning Tree Protocol (RSTP) can improve convergence time but does not affect the root bridge election process. Enabling PortFast is useful for reducing the time it takes for ports to transition to the forwarding state but does not influence the root bridge designation. Similarly, connecting more uplinks does not apply to the priority of the switch—it can improve overall network redundancy, but it won't change election outcomes based on bridge ID.