Which among the following is the source of light in aurora in sky near the earth’s poles?

Answer: [A] Photon emissions in the earth’s upper atmosphere

The aurora borealis is a display of natural light in the sky near the North Pole. It was named after the Roman goddess of the dawn, Aurora, and the Greek name for the north wind, Boreas, by Pierre Gassendi in 1621. It is a result of photon emissions in the earth’s upper atmosphere  from ionized nitrogen atoms regaining an electron, and oxygen and nitrogen atoms returning from an excited state to a low-energy state.

This question is a part of GKToday's Integrated IAS General Studies Module