Answer: D. Anti smoking article written by the National Health Association.
Step-by-step explanation:
Biasness can be define as the process of manipulating the evidences and sources so as to make profit. The biasness can be seen in the advertisement and research works so as to support the sales of a new product or innovation.
D is not biased because the article has been from a authentic source any discrepancy and manipulation cannot be observed as the results are obtain from experimental and observatory trials instead of external influence.