The greenhouse effect keeps the earth’s surface

The correct answer is Option (3) → warm

In the greenhouse effect, gases in the atmosphere hold back the infrared radiation given out by the earth’s surface. So the heat stays near the surface, and the earth stays warm.

NCERT (2026-27):
Infrared Waves – “… Infrared radiation also plays an important role in maintaining the earth’s warmth or average temperature through the greenhouse effect. Incoming visible light (which passes relatively easily through the atmosphere) is absorbed by the earth’s surface and re-radiated as infrared (longer wavelength) radiations. This radiation is trapped by greenhouse gases such as carbon dioxide and water vapour.”