AP Biology Questions....URGANT!?

The first one is probably E because cyanobacteria are also known as blue-green bacteria. For this reason, I would think that two photosystems would be required for the two pigmetns. The second one is most certainly D. Plants evolved from cyanobacteria. Most early prokaryotes were chemoautotrophs. Eukaryotes are way to advanced for that time, and obviously don't produce oxygen. Cellular respiration produces CO2, not O2.