The Following Conceptual Representation

The following conceptual representation

A) Says a purchase can consist of more than one of the same inventory item ID
B) Says one inventory item ID can be used for many specific units of the same type of inventory
C) Requires specific identification of each separate inventory item purchased
D) Says an inventory item ID can not be recorded in this database until it has been purchased
E) Says multiple units of one inventory item ID can be included on the same purchase