The correct answer is: d. Most energy at each level is lost, leaving little for the next.
The trophic pyramid or energy pyramid is graphical representation of relationships between organisms depending on their nutrition. The base of the pyramid has the largest amount of biomass so it can support the energy requirements of the organisms above it (at higher levels). Each higher level in the pyramid is smaller because only about 10% of the available energy is transferred to the next level. So, energy is lost at each level.