Earth's Thermosphere Is The

Earth's thermosphere is the:

A) outermost atmospheric layer in which ultraviolet light from the Sun ionizes atoms.
B) intermediate atmospheric layer in which ultraviolet light from the Sun is absorbed by ozone (O₃) molecules.
C) region of the magnetosphere in which trapped high-energy charged particles spiral along magnetic field lines.
D) layer of molten iron and nickel below the mantle.