Answer is C - crust, mantle, outer core, inner core.
Crust -
Crust is the outermost layer. The thickness of the crust is about 5 - 70 km.
Mantle -
Mantle is the second layer from the Earth's surface. Thickness is about 2890 km.
Mantle can be divided into two parts as upper mantle and lower mantle.
Outer core -
The thickness is about 2400 km. It is made from mostly iron and nickel.
Inner core -
The innermost part of the Earth is inner core. Mainly made from iron-nickel alloy. It is solid sphere which has a radius about 1220 km.
