- A producer produces its own food
- To produce something means to make something
- So, a producer makes its own food

- A producer makes its own food
- Green plants make their own food
- Hence, green plants are a kind of producer

So, green plants are a kind of producer
Since green plants make their own food, they are called
- A producer produces its own food 
- Green plants make their own food 
- To produce something means to make something