Final answer:
Most organizations track inventory using identifiers such as part numbers, item numbers, or SKUs.
Step-by-step explanation:
Most organizations track inventory by an identifier such as a part number, item number, or SKU. Therefore, the correct answer is D. All of the above. Part numbers are typically used to identify specific components or parts of a product, while item numbers are used to identify individual items in a store or warehouse. SKUs (Stock Keeping Units) are unique codes assigned to individual products for inventory tracking and management.