The earth has four layers; the
crust, the mantle, the outer core and the inner core. The Earth’s magnetic
field is the combination from the convection it receives from the outer core
and the Coriolis Effect. The answer is letter A. The outer core is
composed mostly of liquid nickel and iron. It is expected to have that state of
metal because it has a higher temperature. The inner core cannot hold much of
the magnetic field because of its high temperature and high pressure that
exceeds the outer core. The temperature decreases however as the layer goes
outwards.
