According to the law of conservation of matter, matter is never created or destroyed. Yet in a food pyramid the amount of biomass decreases as we move up through the pyramid, from producers to top level consumers. Why?

A) Matter is decomposed at different levels in a food chain.
B) Matter is recycled at each level of the food chain and returned back to the producers.
C) Matter is taken back by the producers after it is left unused by consumers at each level.
D) Matter changes to other forms that might not continue to be a part of the same food chain.