The management of a shoe manufacturing company wants to lower the cost of production by reducing wastage in its manufacturing process. The management believes that the wastage can be reduced substantially through change in quality control program. However, according to a middle level manager, since the waste level per employee has increased significantly after certain changes were made to the program three years ago, making further changes will not bring any benefit.

Which of the following is an assumption on which the manager’s argument depends?

A. The number of employees assigned to the manufacturing department was not significantly higher three years ago than it is at present.
B. The quantity of wastage has not decreased in last 3 years.
C. The company profitability has not declined in the last three years.
D. The change in quality control program may adversely affect the volume of waste per employee.
E. The quality of shoes manufactured by the company has remained the same as it was 3 years ago.