Why are ecological pyramids shaped as pyramids?

A.Because there is a large decrease in the amount of energy or biomass as you move from one trophic level up to the next

B.Because the movement of energy through the biosphere follows a path similar in shape to a pyramid

C.Because decomposers form a wide base of support at the bottom of a food web similar to the base of a pyramid

D.Because food webs are usually triangular in shape