On the Basis of Research Findings,what Do Most Scientists Now

On the basis of research findings,what do most scientists now conclude about the relationship between aluminum and neurocognitive disorder due to Alzheimer's disease?

A) It is almost indisputable.
B) It exists, but the typical levels of aluminum in our environment are so low as to pose a minimal risk.
C) It is very weak if it exists at all.
D) It is fairly strong.