The answer to your question is D never
Answer: The Option "d.returning inventory that is defective or broken" is NOT an example of safeguarding inventory.
Explanation: If we analyze the statements:
a.physical devices such as two-way mirrors, cameras, and alarms - These are all tools intended for protection against possible inventory theft.
b.storing inventory in restricted areas - Restricting access only to inventory-enabled personnel is able to protect the inventory much more than if anyone can access it.
c.matching receiving documents, purchase orders, and vendor's invoice - Controlling each of the purchase documents and performing the physical count reduces the possibilities of inventory differences for losses or errors.
d.returning inventory that is defective or broken - Returning the defective inventory is a post-echo action that occurred due to the unprotection of the inventory, therefore it could not be referred to as an example of inventory protection.
"8.60" (and any subsequent words) was ignored because we limit queries to 32 words.