Concept:Producers are organisms that make their own food, usually through photosynthesis, while non-producers depend on other food sources.
Explanation:Hibiscus is a green flowering plant containing chlorophyll, so it is a producer.
Cactus is a green plant that carries out photosynthesis, so it is a producer.
Spirogyra is a green alga with chlorophyll, so it is a producer.
Mushroom is a fungus that lacks chlorophyll and cannot photosynthesize.
It obtains nutrients from decaying organic matter as a saprophyte.
Thus, mushroom is the only organism that is not a producer.
Answer:B. Mushroom