**Explanation:**

The ecological pyramid is a graphical representation of the trophic levels (feeding relationships) in an ecosystem. It shows the relative amounts of energy, biomass, or number of organisms at each trophic level. There are three types of ecological pyramids: pyramid of energy, pyramid of biomass, and pyramid of numbers.

- Pyramid of energy: This pyramid represents the flow of energy through the trophic levels of an ecosystem. It shows the amount of energy available at each trophic level. The energy is transferred from one trophic level to the next through feeding relationships. The pyramid of energy is always upright because energy is lost as heat at each trophic level, resulting in a decrease in the amount of energy available at higher trophic levels. Thus, the energy pyramid is always erect and upright.

- Pyramid of biomass: This pyramid represents the total dry mass or organic matter (biomass) at each trophic level. It shows the amount of living or organic material present in each trophic level. The biomass pyramid can be either upright or inverted, depending on the ecosystem. In most cases, the biomass pyramid is upright, with the highest biomass at the base (producers) and decreasing biomass at higher trophic levels. However, in some cases, such as in aquatic ecosystems, the biomass pyramid can be inverted, with higher biomass at higher trophic levels due to rapid growth and reproduction of smaller organisms.

- Pyramid of numbers: This pyramid represents the number of organisms at each trophic level. It shows the population size or abundance of organisms at each trophic level. The pyramid of numbers can be either upright, inverted, or spindle-shaped, depending on the ecosystem. In a typical terrestrial ecosystem, the pyramid of numbers is upright, with a large number of producers (plants) supporting a smaller number of herbivores, and an even smaller number of carnivores at the top. However, in some cases, such as in parasitic ecosystems, the pyramid of numbers can be inverted, with a smaller number of parasites supporting a larger number of hosts.

Therefore, the correct answer is option B: Pyramid of energy. The pyramid of energy is always erect and upright because energy is lost as heat at each trophic level, resulting in a decrease in the amount of energy available at higher trophic levels.