Quality control costs can be categorised into internal and external failure costs, appraisal costs and prevention costs. In which of these four classifications would the following costs be included?

- The cost of a customer service team

- The cost of equipment maintenance

- The cost of operating test equipment.

Customer service team Equipment maintenance A Prevention costs Appraisal costs Test equipment Internal failure costs B Prevention costs Internal failure costs Appraisal costs C External failure Internal failure costs Prevention costs costs D External failure costs Prevention costs Appraisal costs