单项选择题
What is the best title for the passage（）
A．The Inherent Weaknesses of the Price System. B．The Complexities of the Price System. C．Credit Terms in Transactions. D．Resource Allocation and the Public Sector.
单项选择题 According to the passage, the price system is related primarily to （）
单项选择题 The paragraph following the passage most likely discusses （）
单项选择题 In the last sentence of the passage, "they" refers to （）
