Earth's outer core is a fluid layer about 2,400 km (1,500 mi) thick and composed of mostly iron and nickel that lies above Earth's solid inner core and below its mantle. Its outer boundary lies 2,890 km (1,800 mi) beneath Earth's surface. ... Unlike the inner (or solid) core, the outer core is liquid. Hope this helps
A. reduce the need to use fossil fuels
The answer is 14.8 hoped this helped