Correct Answer: Chlorine

Solution : The correct option is Chlorine.

Chlorine is not a large component of the Earth's atmosphere. It is found in lower trace levels in the atmosphere, often less than 0.002% (20 parts per million). The gases found in the Earth's atmosphere are nitrogen, oxygen, carbon dioxide, helium, hydrogen, argon, although chlorine is present in atmosphere in low quantity and is typically found in the form of compounds rather than as a pure gas. The Earth's atmosphere is largely composed of 78% nitrogen, 21% oxygen, and trace amounts of other gases such as carbon dioxide, argon, and others.