Final answer:
The work-in-process inventory file is a collection of cost sheets, which are used to track the production costs of products still in the manufacturing process.
Step-by-step explanation:
A work-in-process inventory file is the collection of all b) Cost sheets. Cost sheets provide detailed information about the costs associated with a product as it moves through the production process. These sheets track the direct materials, direct labor, and manufacturing overhead applied to each product or batch of products.
In a manufacturing environment, maintaining accurate work-in-process (WIP) records is crucial for monitoring production progress, managing inventory levels, and determining product costs for financial accounting and reporting. The WIP file serves as a central repository for all the cost information related to unfinished goods.