The correct answer is: D. Mirage.
A mirage is an optical illusion that causes an image of distant objects to appear displaced from their true position. It is most commonly seen in hot, dry regions, where the air near the ground is warmer than the air above it. This difference in temperature causes the light from distant objects to bend, making them appear to be floating in the air.
A rainbow is an optical and meteorological phenomenon that causes a spectrum of light to appear in the sky when the Sun shines onto droplets of moisture in the Earth’s atmosphere. Rainbows can be full circles. However, the observer normally sees only an arc formed by illuminated droplets above the ground, and centered on a line from the Sun to the observer’s eye.
Earthshine is a faint illumination of the dark side of the Moon caused by sunlight reflected from the Earth. It is most easily seen during a lunar eclipse, when the Earth is between the Sun and the Moon.
A halo is an optical phenomenon that appears as a ring or halo around the Sun or Moon. It is caused by the refraction and reflection of light by ice crystals in the atmosphere.