Which statement describes the flow of energy and matter through the terrestrial ecosystem?

a
Energy is gained by organisms at higher levels as they consume other organisms, which causes hawks to be larger than frogs.
b
Energy is lost as heat as it moves up the pyramid from the bottom, which causes there to be fewer hawks than plants.
c
Energy is lost to the environment when organisms die, which causes there to be a larger number of plants due to consuming dead organisms.
d
Energy is gained by producers from soil nutrients, which causes there to be more frogs than herbivore insects.