In an ecosystem

The correct answer is Option (2) → Energy flows and nutrients cycle

Energy flows one way through an ecosystem, from the sun through the trophic levels and is lost as heat; nutrients are used again and again, moving in cycles between living and non-living parts.

Option (1) Energy flows and nutrients Flow — Incorrect. Energy does flow, but nutrients cycle. They are used again and again, moving between living organisms and the soil, air and water.

Option (2) Energy flows and nutrients cycle — Correct. In an ecosystem, energy flows in one direction: from the sun to producers to consumers, and it is lost as heat at each step. Nutrients cycle: they are used again and again, passing between the living and the non-living parts.

Option (3) Energy cycles and nutrients cycle — Incorrect. Nutrients cycle, but energy does not. Energy flows one way from the sun through the trophic levels and is lost as heat at each step.

Option (4) Energy cycles and nutrients Flow — Incorrect. Both are reversed. Energy flows one way and is lost as heat, while nutrients cycle through the ecosystem.

NCERT Extract:
Energy Flow – “… All organisms are dependent for their food on producers, either directly or indirectly. So you find unidirectional flow of energy from the sun to producers and then to consumers.”