The infrared radiation traveling toward earth is
-mostly reflected back out into space
-mostly absorbed and transmitted toward earth's surface
-equally absorbed and reflected
-completely blocked and reflected by the upper atmosphere

Correct B). Mostly absorbed and transmitted toward Earth's surface

The infrared radiation coming from the sun reaches the earth's surface and it warms up the earth's surface. It emits back some of the infrared radiation some of it is absorbed by the gases present in the atmosphere such as carbon dioxide. It is called as greenhouse effect.

If it does not occur then the radiation coming from the earth would be powerful enough to burn skin.