Which of the following Terran units from the RTS game Starcraft was first introduced in the expansion Brood War?

The Medic was first introduced in the expansion Brood War of the RTS game Starcraft. The Medic is a support unit specifically designed to heal and restore health to friendly units. Its introduction in the expansion aimed to enhance the versatility of the Terran army by providing crucial healing capabilities on the battlefield. The Medic became an essential unit in micro-managing and sustaining the Terran forces, allowing players to keep their units alive and maintain prolonged combats.