During a routine check, a network administrator discovers that several switches are incorrectly assuming the role of the central controlling bridge in a redundant network setup. What should the administrator adjust to rectify this situation and ensure only the designated switch serves as the central controller?
Turn off the protocol that prevents network loops on all network devices
Switch all network cables from copper to fiber optic to enhance signal quality
Upgrade the firmware on the switch currently assuming the lead role
Decrease the bridge priority number on the switch intended to serve as the central controller