Answer the following question given this paragraph: 

A food chain is a simple diagram that shows one way energy flows through an ecosystem. You can see an example of a food chain in Figure below . Producers form the base of all food chains. The consumers that eat producers are called primary consumers. The consumers that eat primary consumers are secondary consumers. This chain can continue to multiple levels.


Q: What term is used to describe a simple diagram that shows one way energy flows through an ecosystem?

 Choices:

- water cycle

- food pyramid

- fuel chain

- food chain

A:
food chain
