What Do Astronomers Mean When They Say That the Sun

Multiple Choice

What do astronomers mean when they say that the Sun makes energy by hydrogen burning?

A) The Sun is combusting hydrogen in a fire and releasing energy.
B) The Sun is fusing hydrogen into uranium and releasing energy.
C) The Sun is made of mostly hydrogen at very high temperature.
D) The Sun is fusing hydrogen into helium and releasing energy.
E) The Sun is accumulating hydrogen from the solar wind and releasing energy.