The transfer of energy from one organism to the next in an ecosystem begins with a producer. A producer is an organism that produces its own food. A consumer is an organism in a food chain that obtains energy from producers or other consumers; consumers may be herbivores or carnivores. Which food chain correctly describes the flow of energy in an ecosystem? A) grass→grasshopper→fish→human B) grasshopper→fish→human C) human→fish→grasshopper D) human→grasshopper→fish→grass