A biker is making a turn around the corner. The biker's speed remained constant at 12 miles per hour during the entire turn. Which of the following statements describes the forces on the biker?

The forces were balanced to keep the biker with a constant speed.
The forces were unbalanced as the biker made the turn.
The forces were balanced due to the biker's inertia.
The forces were unbalanced due to the action-reaction pair required to turn.