单选题 What function of the wholesaler is compared to a valve?

A、 Controlling the flow of goods.
B、 Pushing up demand from retailers,
C、 Beating part of the risk for manufacturers.
D、 Selling goods to retailers.

【正确答案】 A

【答案解析】[分析] 推断题型。从第三段的第一句话The manufacturer can then keep up a steady production flow， and the retailer has no need to hold heavy stocks, who can call on the wholesaler for supplies any time．可推断出答案。