The answer is B. Carbon atoms can bond to other carbon atoms. In fact, carbon has four electrons to form four bonds with other atoms, including carbon. Carbon is the most common and used element in the world because it makes up all living things. All four main macromolecules also contain carbon.
I believe the correct answer is Oxygen Gas.
The earth's atmosphere is made up of many different molecules, therefore including the gases. Some common gases are nitrogen, oxygen, and argon, which are only present in traces of percentages. And the gas that occurs as a result of photosynthesis is our answer, oxygen gas.
Hope I could help! :)
Ummmmmmmmmm..... chewing?