Concept:The inner core is composed mainly of heavy metals, primarily iron and nickel.
Explanation:Earth's core is divided into a solid inner core and a liquid outer core.
The bulk of the inner core is made of metallic elements, not light or scattered minerals.
Iron and nickel are the dominant metals in the inner core.
A small amount of lighter elements, such as oxygen or sulphur, may also be present.
Thus, among the given pairs, only iron and nickel correctly describe the inner core composition.
Answer:C. iron and Nickel