Answer:
The correct answer is Option 2: Molten iron and nickel.
The Earth's outer core is primarily composed of molten iron and nickel. This layer is responsible for generating the Earth's magnetic field through the geodynamo process, where the movement of the molten metal in the outer core generates electrical currents that create the magnetic field. It is not composed of molten rock, solid metal, or thick sludge.
Step-by-step explanation: