What was the importance of materials like iron and nickel in Earth’s core formation?

Correct answer: Being heavy metallic materials, they accumulated at the centre

During Earth’s early differentiation, the young planet was extremely hot, and much of its material could melt or move plastically. Gravity then separated materials according to density. Dense metallic elements, especially iron and nickel, moved downward and accumulated near the centre, while lighter silicate materials remained above them and formed much of the mantle and crust. This process produced a dense metallic core surrounded by less-dense layers. Iron and nickel were therefore important because of their high density and metallic nature, not because of any atmospheric or oceanic transformation. Hence, option A correctly explains their role; the other options describe unrelated and scientifically incorrect processes.