Plants absorb the greenhouse gas carbon dioxide during the process of

Photosynthesis

Explanation:

Plants absorb the greenhouse gas carbon dioxide from the atmosphere. The water is taken up from the roots of the plants. The carbon dioxide, water in the presence sunlight produces carbohydrates and oxygen as products in a chemical reaction called as photosynthesis. If the abundance of plants get limited from the biosphere then the abundance of carbon dioxide gas will increase in the atmosphere which will lead to increase in global temperatures as the gas is capable of trapping the heat energy from sun which will lead to global warming.  

i think it would be b. tissue because an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.

i believe the correct answer is d