The correct answer is: D. corona
The corona is the outermost layer of the sun’s atmosphere. It is a hot, tenuous plasma that extends millions of kilometers into space. The corona is visible during a total solar eclipse, when the moon passes between the Earth and the sun. The corona is also visible during solar flares, when the sun releases a burst of energy.
A nebula is a cloud of gas and dust in space. Nebulae can be either bright or dark. Bright nebulae are made up of hot gas that emits light. Dark nebulae are made up of cold gas and dust that absorbs light.
A comet is a small, icy body that orbits the sun. Comets have a long, thin tail that is made up of gas and dust. Comets are most visible when they are close to the sun, because the sun’s heat causes the comet’s ice to vaporize.
An asteroid is a small, rocky body that orbits the sun. Asteroids are much smaller than planets. Asteroids are most common in the asteroid belt, which is a region between the orbits of Mars and Jupiter.
I hope this helps!