Answer:
3. The inner core is made of solid nickel and iron.
Explanation:
This is the statement that best reflects the reality of the Earth's composition. The inner core of the Earth is made of solid nickel and iron. Moreover, this is the hottest part of the planet. In fact, it is considered to be about the same temperature as the surface of the Sun. We owe the discovery of the inner core to Danish seismologist Inge Lehmann.
