Question

what is the major cause of earths magnetic field?
magnetic materials on earths surface
charged particles from the sun
earths magnetic lithosphere
earths liquid outer core

Explanation:

The Earth's magnetic field is mainly generated by the motion of molten iron - nickel alloy in the Earth's liquid outer core. This motion creates electric currents which in turn generate the magnetic field. Magnetic materials on the surface, charged particles from the sun, and the magnetic lithosphere are not the major causes.

Answer:

Earth's liquid outer core