The answer is C. Pyramid of energy
Both Pyramid of numbers and Pyramid of biomass can be inverted, but Pyramid of energy will always stay upright
In pyramid of energy, the 1st level floor of the pyramid will pass 10 % of its energy to the 2nd floor, then the 2nd floor will passed 10% of its energy to the 3rd level and so on
If it's inverted, there would be insufficient energy to pass to begin with, making it really inefficient