Which of the following is not true regarding the general transfer pricing rule?
1) When the market price of a product does not depend on the quality sold by any one producer, opportunity costs are more easily measurable.
2) One difficulty in implementing the general transfer pricing rule is the difficulty in measuring opportunity costs.
3) The general transfer pricing rule provides a good conceptual model for setting transfer prices.
4) When there is perfect competition, the opportunity cost of internal transfers depends upon the quantity sold externally.