What are the numbers that must be placed in the black to balance the chemical equation

1,2,1,2
2,1,1,2
2,1,2,1
1,2,2,1

Which statement is the best summary of the model? a-a series of aerobic and anaerobic reactions take place in cells b- the sun's energy moves through trophic levels in a food chain c-light energy is converted into stored chemical energy plants.d- food molecules are broken down in the cells if living things.