Countries Such as Brazil, India, and Moldova-Well-Known Sources of Organ

Countries such as Brazil, India, and Moldova-well-known sources of organ donors-have banned buying and selling organs. This legal action comes at the risk of driving the trade underground. What idea from Chapter 1 of the text does this story best illustrate?

A) Legal and social forces can eliminate economic forces.
B) Marginal revenue should equal marginal cost.
C) Economic forces always operate despite legal forces.
D) The invisible hand is not always invisible.