Correct Answer: Water vapour

Solution : The correct option is Water vapour.

Water vapour is a significant component of the Earth's greenhouse gases. The concentration of water vapour in the atmosphere can vary widely depending on location, weather conditions, and altitude. On average, water vapour makes up about 0.25% of the Earth's atmosphere by volume. Greenhouse gases are gases in the Earth's atmosphere that can trap heat from the sun, creating a "greenhouse effect."