The answer is “d” (1,000 kcal). As the trophic level increases energy is decreases by 10 times that of the previous level. If a system has 10,000 kcal, then the primary consumer have 10 times less (10,000/10) which is 1,000 kcal. The secondary consumers have 100 kcal and the tertiary have 10 kcal. Only 10% of the energy at each trophic level goes on to the next.
