What are transferred-in costs in a process costing system?

A. Costs of the output of a previous internal process that is subsequently used in a succeeding internal process.

B. Labor costs incurred for transferring employees from another department within the same plant instead of hiring temporary workers from the outside.

C. Ending work-in-process inventory of a previous process that will be used in a succeeding process.

D. Supervisory salaries that are transferred from an overhead cost center to a production cost center.