Would an advertising agency use job order or process costing? What about a cell phone manufacturer?

A. Advertising agency long dash job order costing; Cell phone manufacturer long dash job order costing
B. Advertising agency long dash process costing; Cell phone manufacturer long dash job order costing
C. Advertising agency long dash process costing; Cell phone manufacturer long dash process costing
D. Advertising agency long dash job order costing; Cell phone manufacturer long dash process costing

The job order costing system is used when the service or product offered are significantly different from others. In the case of an advertising agency, no service is the same since no client will require the same advertising campaign.

The process order costing system is used when the service or product offered are similar to others. In the case of a cell phone manufacturer, they might offer a few different models but in essence the products are very similar.