The illustration below indicates that photosynthesis and cellular respiration are both complementary and balanced. An excess of sugars produced fossil fuels like coal and petroleum; this suggests that in the past:

The rate of photosynthesis was more than the rate of respiration

Explanation:

Photosynthesis has to do with the synthesis of sugar molecules from inorganic products such as water and carbon dioxide. Respiration on the other hand has to do with breaking down of the sugar molecule from photosynthesis to release the energy locked up in the sugar for various metabolic processes in the plant's body.

If both processes are balanced, there will be no net sugar production. Hence, if an excess of sugar produced fossil fuels, it thus means that there was net production of sugar in the past. The rate of photosynthesis was more than the rate of respiration in the past.

what's the question?

carbon atoms, hydrogen, oxygen, and nitrogen.