The trapping of heat by carbon dioxide and water vapor is known as the_

Greenhouse effect. 
Here is what the greenhouse effect does:the trapping of the sun's warmth in a planet's lower atmosphere due to the greater transparency of the atmosphere to visible radiation from the sun than to infrared radiation emitted from the planet's surface.

Adozen is 1221/12 = 1.751.75 x 12 = 21therefore, 1.75 is the answer.

C: plants and animals