The increasing amount of carbon dioxide in the air is slowly raising the temperature of the atmosphere, because it absorbs

The answer is D. CO2 is a greenhouse gas because it is largely transparent to incoming visible and short-wave solar radiation but absorbs infrared (long-wave) radiation. That absorbed heat is re-emitted, so less escapes to space and the lower atmosphere warms. The question's wording says 'solar', but the infrared that matters physically is the outgoing terrestrial infrared from the Earth's surface, so keep that nuance in mind.

• A is wrong. CO2 does not absorb water vapour. Water vapour is itself a major greenhouse gas, which is why it is a feedback factor, but that is a different statement.
• B is wrong. UV radiation is absorbed mainly by stratospheric ozone (the ozone layer), not by CO2.
• C is wrong. Most solar radiation reaches the surface; CO2 does not absorb all of it. Absorbing 'all' radiation would make the gas a black body, which is not the case.

This links to the Environment and Climate Change syllabus: the greenhouse effect, the carbon budget, and the Paris Agreement's temperature targets. For Mains, it helps in answering questions on the causes of global warming and on the role of forests and carbon sinks.

Trap: Aspirants often pick B because UV is the 'harmful' radiation linked with the atmosphere, or A because water vapour is the most abundant greenhouse gas. Ask which gas absorbs which band of radiation.