D
. Energy flows from the Sun or from rocks through the primary producers and the successive levels of consumers.
Explanation:
Energy flows only through the sun not the rock because sun is the ultimate source of energy which can be used by the plants for making their own food in the form of glucose during the process of photosynthesis. This plant is then eaten by primary consumer known as herbivore. These primary consumer is eaten by secondary consumer is called carnivores. The tertiary consumer feeds on the secondary consumer and so on. In the end, decomposers feed on the dead bodies of animals and releases nutrients which can be used again by the plants for making food.
