The sentence: "Newspapers are reducing costs wherever they can." in the Passive Voice would be:

a$)$ Costs have being reduces by newspapers wherever they can.

b$)$ Costs have being reduced by newspapers wherever they can.

c$)$ Costs are being reduced by newspapers wherever they can.

d$)$ Costs are reduced by newspapers wherever they can.

e$)$ Costs are reducing by newspapers wherever they can.