Answer: Plants
Step-by-step explanation:
The organism that is producer in the food web is Plant. These organism belongs to the group of autotrophic organism.
These organism use sunlight and convert it into chemical energy. This energy is used by producers and consumers to carry the various metabolic processes of the body.
Only producers have the ability to make food and hence, they do not depend on any other organism for their energy needs.
Hence, the correct answer is "option D".