Data from a study about the effects of certain diets on people's health is primary source. i.e, option A is correct.
<h3>What source is a primary source?</h3>
Primary sources are documents, images or artifacts that provide firsthand testimony or direct evidence concerning an historical topic under research investigation. Primary sources are original documents created or experienced contemporaneously with the event being researched.
Data about the fact of certain diets on people health is primary source.
