Answer and Discussion

MTM 1-3 (Drill Bit):

• The best answer would be (d) Steel, as steel, which is an alloy of iron and carbon, can be given a very hard edge, an important quality for a cutting tool

Discussion:

Aluminum is light weight but only moderately hard. Gold is very heavy(and very valuable) but is very soft or malleable. Copper is moderately soft, and was used in ancient times as a cutting tool, but was soon replaced by bronze, then iron, then steel, each having a harder edge than its predecessor.