(A) direction of a force but not its magnitude.

(B) output work relative to the input work.

(C) amount of input work relative to the output work.

(D) magnitude of a force but not its direction.

The correct answer is (B) output work relative to the input work.

Simple machines are devices that make it easier to do work. They do this by changing the direction or magnitude of the force that is applied to an object. In all cases, the output work (the work done by the machine) is less than the input work (the work done by the person using the machine). This is because some of the input work is lost to friction and other inefficiencies.