Which trophic level is the starting point for energy entering the food web

Hey you have marked the correct answer.

This ia becacuse first the producer produces its food itself.And it ia eaten up by consumers. And again both producer and consumer are decomposed into simple form by decomposer after their death and that simple particles are up taken by the producer and the same procedure happens.

In this way, the starter if the food web is producer.

But among the producers, primary producer comes first.

b. the carbon cycle ensures living things have a source of hydrogen