The correct option is D All of the above
An ecological pyramid is the graphic representation of an ecological parameter (number, biomass, energy) at various trophic levels of a food chain with producers at the base, herbivores in the middle and carnivores at the top tiers. It can be upright, inverted or spindle-shaped. These pyramids show the relationship between different trophic levels in an ecosystem. Thus, the correct answer is option D.