1. When cleaning aluminum and magnesium engine parts, it is inadvisable to soak them in solutions containing soap because A. some of the soap will become impregnated in the surface of the material and subsequently cause engine oil contamination and foaming. B. the soap can chemically alter the metals causing them to become more susceptible to corrosion. C. the parts can be destroyed by dissimilar metal electrolytic action if they are placed together in the solution for more than a few minutes.