A class 2 lever is characterized by the load being located between the effort (force applied) and the fulcrum (pivot point).
Among the examples provided, salad tongs picking up salad represent a class 2 lever. In this case, the load is the salad, the effort is applied by squeezing the tongs, and the fulcrum is the pivot point where the two arms of the tongs are joined together.
The other examples do not fit the criteria for a class 2 lever:
- Tweezers plucking hairs (class 1 lever).
- A car door being opened and shut (class 3 lever).
- A screwdriver opening a paint can (class 1 lever).
So, salad tongs is the correct answer.