In a process cost system product costs are summarized:

A) on job cost sheets.
B) on production cost reports.
C) after each unit is produced.
D) when the products are sold.

In a process cost system, product costs are summarized on production cost reports. These reports accumulate the costs incurred during a specific period for each department or process. They include direct materials, direct labor, and overhead costs to determine the total cost of production for a particular period.