Option 1 states that the energy flow in an ecosystem starts with producers, then goes to decomposers, and finally to consumers. This is incorrect because energy flow always starts with producers, but decomposers break down the remains of dead organisms, releasing nutrients back into the ecosystem, not energy.

Option 2 states that the energy flow starts with decomposers, then goes to consumers, and finally to producers. This is also incorrect because producers are the primary source of energy in an ecosystem, so energy flows from producers to consumers, and not the other way around.

Option 4 states that the energy flow starts with consumers, then goes to producers, and finally to decomposers. This is not accurate because consumers obtain energy by consuming other organisms, so they do not transfer energy to producers.

Therefore, option 3 is correct. It accurately states that the energy flow in an ecosystem starts with producers, then goes to consumers, and finally to decomposers.