Question

Which of the following is not a green house gas?
A) Water vapor
B) Carbon dioxide
C) Methane
D) Oxygen

Answer 1

Greenhouse gas, any gas that has the property of absorbing infrared radiation (net heat energy) released from the Earth's surface and re-radiating it back to the Earth 's surface, thereby leading to the greenhouse effect.

Complete answer:

Greenhouse gases, while being just a fraction of all greenhouse gases, have a profound impact on the energy budget of the Earth system. Concentrations of greenhouse gases have changed greatly over the course of Earth's history, and these changes have contributed to major climate change over a wide range of timeframes. In general, greenhouse gas concentrations were especially high during warm periods and low during cold periods.
Carbon dioxide, Methane, chlorofluorocarbon, sulphur dioxide are examples of Greenhouse gas. Whereas oxygen and hydrogen are not examples of greenhouse gases.
A variety of processes have an effect on greenhouse gas concentrations. Some, such as tectonic operations, operate on timescales of millions of years, while others, such as trees, soil, wetland, and ocean springs and sinks, operate on timescales of hundreds to thousands of years.
The effect of each greenhouse gas on Earth's environment depends on its chemical composition and relative concentration in the atmosphere. Some gases have a high capacity to absorb infrared radiation or are present in large quantities, while others have slightly lower absorption capacity or are present only in trace amounts.
Water Vapor is the most active greenhouse gas in the Earth's atmosphere, but its behaviour is radically different from that of other greenhouse gases. The primary function of water vapour is not as a direct agent of radiative forcing, but rather as a response to climate change — that is, as a response within the climate system that affects the continued operation of the system.
$CO_2$ is the most important greenhouse gas in the world. Natural sources of atmospheric $CO_2$ include outgassing from volcanoes, combustion and natural degradation of organic matter, and respiration from aerobic ( oxygen-using) organisms.

Thus the correct answer is option (D) Oxygen.

Note: Climate models indicate that natural warming is intensified by human activities that increase concentrations of greenhouse gases in the atmosphere and increase the greenhouse effect. The increase in the atmospheric concentration of greenhouse gases, accentuating the global natural greenhouse effect, is often referred to as the enhanced greenhouse effect or Global Warming.