Multiple choice:
for the earliest humans , the only strategic mineral materials were:
a) copper and tin b) water and salt
c) iron and gold d) muscovite and bronze

a)Copper and tin

Explanation: Copper and tin came into use at very early ages in the form of utensils, ornament etc. They were discovered in a way that it is possible for the people of early ages to extract these metals and melt them to give it some kind of shapes and utilize it for their daily living.People also started using these metals in the form of alloys as well which expanded the used of metals like copper, tin , bronze etc. Thus, correct option is copper and tin.