Which of the following statements is true of the supply chain?

A) All members of the supply chain of a firm must have geographical proximity.
B) Every supply chain must include suppliers, manufacturers, distributors, retailers, and customers.
C) Each organization in the chain is connected to just one company up the chain (toward the supplier) and down the chain (toward the customer).
D) The supply chain includes transportation companies, warehouses, and inventories.

D) The supply chain includes transportation companies, warehouses, and inventories.