It takes 86 joules of energy to raise a box 2 meters using the pulley setup shown above.

Without the pulley, the box can be raised 2 meters using only 82 joules of energy. What could explain this 4-joule difference?

A.
When raising the box using the pulley, 4 joules of mechanical energy are broken down into protons, neutrons, and electrons.
B.
When raising the box using the pulley, 4 joules of mechanical energy are transformed into water.
C.
When raising the box using the pulley, 4 joules of mechanical energy are converted into heat energy due to friction.
D.
When raising the box using the pulley, 4 joules of mechanical energy are destroyed.