Answer:
A. Trapping energy from the sun in the earth's atmosphere
Explanation:
The gases, or rather the greenhouse gases, are gases that have the ability to trap the heat into the earth's atmosphere. When there's enough of these gases in the atmosphere, the heat that is reflected from the earth's surface and heads back toward the space is trapped in big portion by them. As the heat is trapped and accumulated, the atmosphere become warmer, thus the global climate changes gradually and it becomes warmer. The gases that have the biggest influence in this process are the carbon dioxide and the methane.
