Evidence of planetary differentiation is clearly seen in which structure of Earth?

Correct answer: Heavy metals in core and lighter layers above

Direct answer: Option A, heavy metals in the core and lighter layers above. Planetary differentiation means that, when the young Earth became sufficiently hot and partly molten, materials separated according to density. Dense substances moved downward under gravity, while lighter silicate materials remained nearer the surface. This produced broad internal layers: a metallic core, a mantle and a crust. Option A is correct because the concentration of heavy iron and nickel in the core, with lighter rocky materials above, is clear evidence of differentiation. Option B, rings of the Sun, is not an Earth structure and does not show Earth’s internal separation. Option C, a tail of the Moon, is not a normal lunar structure and is unrelated to planetary layering. Option D, oceans of the Milky Way, is scientifically meaningless; the Milky Way is a galaxy, not an object with oceans. Exam cue: differentiation means separation by density—heavy material sinks and light material rises.