The following diagram represents the behaviour of one element of cost. Which ONE of the following statements is consistent with the above diagram?
A.Annual factory power cost where the electricity supplier sets a tariff based on a fixed charge plus a constant unit cost for consumption but subject to a maximum annual charge. B.Weekly total labour cost when there is a fixed wage for a standard 40 hour week but overtime is paid at a premium rate. C.Total direct material cost for a period if the supplier charges a lower unit cost on all units once a certain quantity has been purchased in that period. D.Total direct material cost for a period where the supplier charges a constant amount per unit for all units supplied up to a maximum charge for the period.