Which of the following is a greenhouse gas?A ArgonB NitrogenC OxygenD Water vapour

The answer is D. Water vapour.

Here's why:

Greenhouse gases are gases in Earth's atmosphere that trap heat. They let sunlight pass through the atmosphere, but they prevent the heat that the sunlight brings from leaving the atmosphere. The main greenhouse gases are:

• Water vapor
• Carbon dioxide
• Methane
• Nitrous oxide
• Ozone

Among the options given, only water vapour is a greenhouse gas. Argon, Nitrogen, and Oxygen are not considered greenhouse gases because they are virtually transparent to thermal radiation and do not absorb thermal infrared energy. They do not contribute to the greenhouse effect.

The answer is D. Water vapour. Water vapour is considered a greenhouse gas because it contributes to the greenhouse effect, a process where gases in Earth's atmosphere trap the Sun's heat, causing the planet to become warmer.