JT Engineering makes widgets. Widgets first go through the Smelting Department and then go through the Polishing Department. Recent process improvements have enabled JT to increase its output in both departments. How will this impact JTs manufacturing costs for the period?

A : It will cause manufacturing costs to decrease in the Smelting Department and increase in the Polishing Department.

B : It will cause manufacturing costs in both departments to increase.

C : It will cause manufacturing costs to increase in the Smelting Department and decrease in the Polishing Department.

D : It will cause manufacturing costs in both departments to decrease.