Question

In order for work to be done, what three things are necessary?

Answer 1

Work is the application of force to an object, and the object moves in the direction of the force applied.

A) is right out because of the opposite direction
C) says something about power, so that's easy to negate
B) indicates balanced forces, and motion, so that's not really possible

D) is the correct answer, because it has all three aspects: Force, Motion, Movement in the same direction of the force.