This is confusing, help please

Could someone me with number one you

Which organelles are labeled d, and what is one feature that distinguishes them from the other labeled organelles chloroplasts the only organelles that produce sugars from sunlight mosomes, only found in animal and bacterial cells centricles only found in animal cells mitochondra, the only energo-generating structures found in cells

Which process in respiration happens first? a)pyruvate processing b)electron transport chain c)krebs cycle d)glycolysis