某建筑公司通过不同的方式与甲乙丙丁四家公司签订了仲裁协议其中无效的仲裁协议是（）。

A.争议发生之后与甲达成的仲裁协议

B.争议发生前与乙达成的仲裁协议

C.与丙在合同中约定的仲裁条款

D.与丁口头订立的仲裁协议

"What does the middleman do but add to the price of goods in the shops " Such remarks are aimed at the intermediate operations between manufacturers and final customers. This practice usually attracts a lot of attention from the public and the press and the operation most talked about is what is often called wholesaling.The wholesaler buys goods in large quantities from the manufacturers and sells them in smaller parcels to retailers, and for this service his selling price to the retailer is raised several percent higher. But his job is made more difficult by retail demand not necessarily running level with manufacturers’’ production. Because he adjusts or regulates the flow of goods by holding stock until required, he frees the manufacturer, to some extent, from the effect on production of changing demand and having to bear the whole risk.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. This wholesale function is like that of a valve in a water pipe. The middleman also bears part of the risk that would otherwise fall on the manufacturer and also the retailer.The wholesaler provides a purely commercial service, for which he is too well rewarded. But the point that is missed by many people is that the wholesaler is not just someone adding to the cost of goods. It is true one could eliminate the wholesaler but one would still be left with his function: that of making sure that goods find their way to the people who want them.

Which of the following statements is true

A．People cannot do without the wholesaler’s function.

B．The function of the wholesaler does not add to the cost of goods.

C．The wholesaler helps to reduce the price of goods in shops.

D．The wholesaler is well paid for his commercial service.