For a Service Business,the Minimum Cardinalities Between Sales Event and Inventory

Multiple Choice

For a service business,the minimum cardinalities between Sales event and Inventory entity are most likely both 0 for all except which of the following reasons?

A) Service businesses don't sell inventory,they only use inventory to perform services.
B) A sale doesn't have to include any inventory.
C) Inventory can exist that hasn't been part of a sale yet.
D) Some services only require labor.