ANSWER:
C. Cactus to Kangaroo Rat to Rattlesnake to Hawk to Fungus
Step-by-step explanation
Living organisms in an ecosystem obtain energy by feeding on one another. As one organisms feeds on the other, ENERGY FLOWS. However, the flow of energy is UNIDIRECTIONAL. The flow of energy is represented by a FOOD CHAIN where the arrow signals which organism is feeding on which.
According to this question, a typical example of energy flow in a terrestrial ecosystem is as follows:
Cactus → Kangaroo rat → Rattlesnake → Hawk → Fungus
In the above food chain, energy flows as cactus plant (producer) is fed on by kangaroo rat (primary consumer), which is fed on by rattlesnake (secondary consumer), which is fed on by hawk (tertiary consumer). Hawk is decomposed by fungi (decomposer) when it dies. Energy flows in this direction.
Hence, an example of the way energy flows in an ecosystem is represented by Cactus to Kangaroo Rat to Rattlesnake to Hawk to Fungus