Hummer Motors, the manufacturer of the H2 and H3 vehicles, exercises some degree of influence over the prices that retail dealers in the Hummer network can charge for the vehicles. Which of the following is most correct? A. It is generally more difficult to prove this type of restraint of trade, because the courts have generally be unwilling to allow proof by circumstantial evidence alone. B. Intrabrand restraint of trade tends to inhibit interbrand competition. C. Both A and B are correct. D. Neither A nor B are correct.