Scientists calculated the net primary productivity at two different forest sites. Both forests have the same gross primary productivity. Forest A has a net primary productivity of 1,650kcal/m^2/year, and forest B has net primary productivity of 1,110kcal/m^2/year. Which of the following statements is best supported by the data?
a. Forest A has a higher rate of decomposition by bacteria than forest B.
b. Forest A has more biodiversity than forest B.
c. Forest A producers have lower rates of cellular respiration than forest B producers.
d. Forest A producers have more biomass than forest B producers.

Net Primary Productivity is a term that is used to express the difference between CO2 that is taken in by the plant with photosynthesis minus CO2 that the plant releases.

The two forest sites given in the example may not have the same biodiversity and the same species of plants so we can't be sure of option B.

Again for the same reasons, we can't be sure of option D because we do not know the specific plant species in each forest since they are in different areas.

Option A can be ruled out for the same reasons, the lack of information about the forest sites, since we do not know the death rate of the plants in either of the forests.

Option C can be true because forest A has a higher net primary productivity rate which can be an indication of lower respiratory activity hence lower CO2 production, resulting in the given higher net primary productivity.

I hope this answer helps.