Final answer:
Medical clinics are the most suitable for a job costing system because they offer customized services that vary by patient, unlike the more uniform and continuous production processes of other industries mentioned. Correct option is C.
Step-by-step explanation:
The industry more suitable for using a job costing system is C. Medical clinics. Job costing is perfect for situations where services or products are customized or unique, which is typical in medical clinics where treatments and procedures vary greatly from patient to patient.
Chemical plants, petroleum product manufacturing, cement manufacturing, and food processing tend to be more continuous and process-oriented, where each unit of product is relatively uniform and production runs are long, thus better suited for process costing methods.