Answer:
O by excretion of waste and the death of the top consumer
Step-by-step explanation:
The top consumers in the food web pass energy and matter back to the next trophic level when they excrete waste products and also when they die.
Excretion is the passing out of waste materials of metabolism.
During the death of an organism, organic materials are liberated back into the ecosystem. Carbon is released into the soil, carbon dioxide into the atmosphere etc.
These materials are then recycled back into the ecosystem by the activities of plant and special organisms called decomposers. These organisms feed on dead animals especially.