Which of the following statements correctly differentiates between process costing and job costing?

a. A process costing system is used by companies that make unique, one-off products to order with a flexible process; it tracks costs by processing department. On the other hand, a job costing system is used by companies that produce identical products, or jobs, and tracks costs by jobs.

b. A process costing system is used by companies that produce similar or identical units of a product while employing a flexible, ever-changing process; it tracks costs by work-in-process inventory accounting. On the other hand, a job costing system is used by companies that produce unique products, or jobs, and tracks costs by cost of goods inventory accounting.

c. A process costing system is used by companies that produce similar or identical units of a product while employing a flexible, ever-changing process; it tracks costs by cost of goods inventory accounting. On the other hand. a job costing system is used by companies that produce unique products, or jobs, and tracks costs by work-in-process inventory accounting.

d. A process costing system is used by companies that produce similar or identical units of a product in batches while employing a consistent process; it tracks costs by processing department. On the other hand, a job costing system is used by companies that produce unique products, or jobs, and tracks costs by jobs.