D. Ultraviolet rays from the sun are prevented from reaching Earth.
surface.
Explanation:
What little is known is that the Earth's magnetic field creates the so-called "magnetic shield" that provides protection against some other dangerous forms of radiation, namely cosmic rays and solar wind.
While there is no danger of losing the Earth's gravitational field, the Earth's magnetic field is declining faster than any other geophysical phenomenon. This continuous loss of the Earth's magnetic field, and the associated increase in harmful radiation, are beyond human control.
