The Sun spins on its axis. The Sun is located outside the Milky Way galaxy. The Sun is part of the Big Dipper. The Sun produces light and energy in a nuclear reaction.
The Sun is classified as a star. Which characteristic identifies the Sun as a star?

Options:
- The Sun spins on its axis.
- The Sun is located outside the Milky Way galaxy.
- The Sun is part of the Big Dipper.
- The Sun produces light and energy in a nuclear reaction.

The Sun produces light and energy in a nuclear reaction.