In graph two, 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?

Oxygen.

Explanation:

Oxygen is the gas that is increased in concentration due to photosynthetic activities of plants and algae because in the process of photosynthesis, plants and algae absorb carbondioxide gas into the body and as a result, oxygen gas is produced. Some amount of oxygen is used by the plants in the process of respiration while the remaining is released in the atmosphere through stomata.

materials water oxygen those are the things i can think of in this moment.

i have to report this, it doesn't relate to biology