The correct option is A Energy pyramids demonstrate a 90% loss in energy at each step up the pyramid.
According to the ten per cent law, only 10 per cent of the energy entering a particular trophic level is available for transfer to the next higher trophic level. An energy pyramid is the illustration of the reduction in energy as we move through each feeding (trophic) level in an ecosystem. And as 90 per cent of energy is lost at each step, there is a gradual reduction in energy from the base of the pyramid comprising of producers to the apex comprising of predators.