HELP! I NEED HELP TO UNDERSTAND THIS! In this graph below, Label A represents the gases hydrogen sulfide, methane, and carbon dioxide. What gases are represented by label B and how do these gas levels relate to the evolution of photosynthetic organisms?

answer is: nuclear fusion produces elements that are heavier than helium.

nuclei combine to form a heavier nucleus, releasing energy.  

for example, fusion of hydrogen atoms at the sun.  

this fusion nuclear reaction is in the inner core of the sun and hydrogen (atomic number 1) is conveted into helium (atomic number 2).  

the inner core is the central region of the sun and all solar energy is produced in the core by nuclear fusion.