All of the Following Statements Are True EXCEPT

All of the following statements are true EXCEPT:

A) spray washers have skimmers to remove oily contaminants from the surface of the solution.
B) sludge can be neutralized and solidified with chemicals so that it can be disposed as nonhazardous waste.
C) alkaline cleaning will remove rust and scale, but acid cleaners will not.
D) sandpaper is sometimes used to clean machined surfaces but should not be used on bimetal engines that have super smooth head and block surfaces.