Gross primary productivity, or GPP, is the rate at which solar energy is captured in glucose molecules during photosynthesis. Producers such as plants use some of this energy for metabolism and some for growth. Energy is transferred between trophic levels when one organism eats another. However energy transfers are never 100% efficient. Therefore, each trophic level has a successively smaller energy pool from which it can withdraw energy. Determine the amount of energy for the spiders, a secondary organism in the food chain if the Gross Primary Production (GPP) starts at 2,500,000 J of energy.

A) 1,250,000 J
B) 2,500 J
C) 250,00 J
D) 250 J