Why is the Earth's magnetic field important?
A. It is not important.
B. It prevents the seafloor from spreading too far.
C. It is the force that causes the tectonic plates to move.
D. It deflects solar wind and cosmic rays that would harm life on Earth.
Significance. Earth's magnetic field deflects most of the solar wind, whose charged particles would otherwise strip away the ozone layer that protects the Earth from harmful ultraviolet radiation.
