Answer
(e)
Work Step by Step
Net Primary Productivity (NPP) represents the amount of carbon (or energy) that plants store after accounting for their own respiration.
Gross Primary Productivity (GPP) is the total carbon fixed during photosynthesis (sunlight).
Respiration is the carbon released by plants in the dark (or anytime they use energy).
So, NPP = GPP − Respiration — this is the carbon available for growth and consumption by herbivores.
The answer is (e).
