Which of the Following Best Explains 'Pay for Production

Which of the following best explains 'pay for production'? 

A)  Payment is made monthly based on units supplied. 
B)  Payment is made by the manufacturer on the basis of labour costs of the component supplier. 
C)  The manufacturer only pays the supplier for the components which have actually been consumed during the production of a given day or batch. 
D)  Payment is based on the number of hours required for the production of each unit of the component.