Final answer:
The collection of all job cost sheets is known as the work-in-process file, which details the materials, labor, and overhead costs for ongoing jobs in job costing systems.
Step-by-step explanation:
The collection of all job cost sheets is defined as d. work-in-process file.
Job costing is a cost accounting system used to assign costs to individual units or groups of products or services as they are produced. In this system, a job cost sheet records the materials, labor, and overhead costs associated with a particular job. These sheets collectively provide detailed information about the costs incurred for jobs that are currently in progress, hence the term work-in-process (WIP). This information is crucial for tracking the cost of ongoing work and is used in the calculation of the cost of goods manufactured, which eventually contributes to the assessment of the cost of goods sold and inventory valuation.