The correct sequence of energy transfer among living organisms in an ecosystem is

Analyze the question: It asks for the order in which energy moves through living organisms in an ecosystem.

Concept: Energy enters an ecosystem from the sun. Only green plants and other photosynthetic organisms can capture it, and they convert light energy into chemical energy (food). From there, the energy moves along the food chain:

• Producers (green plants, algae) make food by photosynthesis. They are the first link, so energy starts with them.
• Consumers (herbivores, then carnivores and omnivores) get energy by eating producers or other consumers. Primary consumers eat producers, and secondary and tertiary consumers eat other animals.
• Decomposers (bacteria, fungi) break down dead plants and animals and the waste of both producers and consumers. They get their energy last, from the remains of the organisms before them.

Step by step:

1. Who captures energy first? Producers.
2. Who feeds on the producers? Consumers.
3. Who acts on the dead remains of both? Decomposers.

So the sequence is: Producers → Consumers → Decomposers

Checking the options:

• A, B and C start with consumers or decomposers, which cannot capture energy from the sun, so they are wrong.
• E puts decomposers before consumers, which is the wrong order.
• D matches the correct sequence.

Exam tip: Remember "PCD": Producers, Consumers, Decomposers. Energy always starts with the sun and the producers, and ends with the decomposers. Any option that doesn't begin with producers can be eliminated immediately.