Concept:Consumers are living organisms that cannot make their own food and depend on other organisms for nutrition, while producers make their own food.Explanation:Earthworm, bacteria, and Rhizopus obtain food from dead or decaying organic matter, so they act as consumers or decomposers.Spirogyra is a green alga containing chlorophyll, so it can make its own food by photosynthesis.Therefore, Spirogyra is a producer and not a consumer.Answer:B. spirogyra