China's futures exchange generally has the following provisions on the position limit system: ① The exchange can determine the position limit of each variety according to the specific conditions of different futures varieties; (two) the combination of member position restrictions and customer position restrictions to control market risks. ③ The Exchange implements the examination and approval system for hedging trading positions, and the positions are not restricted; (4) When the same customer opens positions in different futures companies, the total positions in a contract shall not exceed the position limit of the customer; ⑤ If the positions of members and customers reach or exceed the position limit, they shall not open positions in the same direction. Therefore, choose D in this question.