Food chains transfer energy unidirectionally from producers to top consumers

Steps:

• Identify the starting point: Food chains begin with producers that make their own food.
• Note the next level: Herbivores (primary consumers) eat producers.
• Add carnivores: Secondary consumers (carnivores) eat herbivores; tertiary consumers (carnivores) eat other carnivores.
• Check for linear flow: The sequence must show one-way progression without cycles or incorrect roles.

Why C is correct:

• It matches the definition of a food chain as a linear sequence starting with producers, followed by herbivores, then carnivores at successive levels, showing energy flow from autotrophs to heterotrophs.

Why the others are wrong:

• A: Starts with decomposer, but food chains begin with producers, not organisms that break down dead matter.
• B: Ends with decomposer after carnivore, but decomposers act on waste/dead organisms separately, not as part of the consumer chain.
• D: Includes producer eating producer, violating the rule that producers do not consume other producers.

Final answer: C