The Doran Company, which produces component parts for elevators, has co$-$located its engineering, logistics$,$ and procurement ivisions. Which of the following describes its demand$-$supply integration?

a$.$ Costs, more than customer specifications, determine which raw materials are placed into production.

b$.$ The promises that salespeople make to customers can be delivered by the company's logistics arm.

c$.$ The company gains efficiencies from ordering and using only those materials that lead directly to sales.

d$.$ Raw material inventories are always stocked well above the levels dictated by production capacity.