The Heliosphere Is The

The heliosphere is the:

A) region surrounding Earth, formed where its magnetic field repels the solar wind.
B) region in the solar interior within which low-frequency "5-minute" sound waves continuously bounce around.
C) solar atmospheric layer between the chromosphere and the corona.
D) protective region containing the Sun and planets created by the solar wind, which prevents penetration by much of the radiation from outside the solar system.