In a lever system, Class 2 levers are designed to increase the force that must be applied. This is because in a Class 2 lever, the load is located between the effort and the fulcrum, allowing for a mechanical advantage that increases the output force.
Class 1 levers can sometimes also provide a mechanical advantage, but it depends on the specific arrangement of the load and effort relative to the fulcrum. Class 3 levers, on the other hand, typically require a greater effort to lift a smaller load, as the effort is applied between the load and the fulcrum.
So, the correct response would be Class 1 and 2, but it's primarily Class 2 levers that are known for increasing the force applied.