Scientists are uncertain whether is an essential mineral for humans.

Scientists are uncertain whether VANADIUM is an essential minerals for humans.
Scientists have not been able to come to an agreement about the status of vanadium as an essential trace element in human nutrients. Previous studies have submitted that vanadium play some role in hormone, cholesterol and blood sugar metabolism.

The answer Is D

Explanation:

A producer like a plant can make its own food while a consumer (who eats other things) cannot