Which of the following is an example of an electric force acting at a distance?

a.
pam applies a force to the head of a nail by pounding it with a heavy, iron hammer. the nail then wedges itself between the fibers of a wooden board.

b.
pam jumps out of an airplane. air rushes past her body a very high speeds as she falls. she then opens her parachute and feels an upward force.

c.
pam rubs a glass rod with wool, then moves the rod over a pile of small paper scraps. the scraps leap into the air and stick to the rod.

d.
pam applies a twisting force to the steering wheel of her car. this force pushes on tubes filled with fluid, which then push the wheels of her car to one side.