Which simple machine allows for lifting a load with minimal effort by changing the direction of the force applied?

The correct choice is a pulley because it is specifically designed to change the direction of the force applied to lift a load. When a pulley is used, the effort can be applied downward, which allows a user to pull down to lift an object up. This is beneficial because it often requires less effort than lifting the load directly against gravity. The mechanical advantage of a pulley system can also be increased by using multiple pulleys together, which further reduces the effort needed to lift heavier loads.

In contrast, other simple machines may assist in lifting or moving loads but do not primarily serve the function of changing the direction of the applied force in the same way. A lever allows for lifting by distributing the load, but it primarily works by providing a fulcrum around which the lever pivots. A screw converts rotational motion into linear motion, but it does not primarily focus on changing the direction of force. An inclined plane helps to lift loads by spreading the effort over a longer distance but does not change the direction of the force applied in a straightforward manner like a pulley does.