Question

according to the article, what valid claim came from the national research council?
there is no association between fluoride exposure and increased cancer risk in humans.
there is a possible link between fluoride exposure and increased cancer risk in humans.
there is a definite link between fluoride exposure and increased cancer risk in humans.

Explanation:

The National Research Council has studied the relationship between fluoride exposure and cancer risk in humans. Scientific consensus often leans towards lack of association as there is not enough evidence for a link.

Answer:

There is no association between fluoride exposure and increased cancer risk in humans.