Please verify if the below is correct:

Identify the following types of quality costs by category, for example, prevention costs:

1. Inspection of materials Prevention cost
2. Return of product External failure cost
3. Discounts due to defects External failure cost
4. Inspection of reworked units Internal failure cost
5. Training of quality-control technicians Prevention cost
6. Engineering design Prevention cost
7. Staffing of complaint phone-lines after sales External failure cost
8. Scrap Internal failure cost

Thank you