A kanban system is an important mechanism for lean system management. Which one of the following statements regarding the operation of a kanban system is TRUE?

a$.$ A typical kanban used in the JIT system includes information such as item number, unit price, competitor's product name, and its price.

b$.$ A kanban can be used to set the order quantity but not the inventory level.

c$.$ A kanban and a container move as a pair once production begins at the fabrication process.

d$.$ An empty container can be exchanged for a full container at the storage location even though no kanban is on the full container.