We need to take into account things which Are already mentioned in passage.no new element is required
A) Fluoride-bearing minerals are not the primary source of fluoride found ingroundwater.
primary source-new element so out [/]
(B) Rainfall does not affect fluoride concentrations in groundwater.[b] its too strong.we are not sure about this as we have info only when rainfall held constant
(C) Sodium-bearing minerals dissolve at a faster rate than fluoride-bearing minerals. not sure as we know where flouride
...
A) Fluoride-bearing minerals are not the primary source of fluoride found ingroundwater.
primary source-new element so out [/]
(B) Rainfall does not affect fluoride concentrations in groundwater.[b] its too strong.we are not sure about this as we have info only when rainfall held constant
(C) Sodium-bearing minerals dissolve at a faster rate than fluoride-bearing minerals. not sure as we know where flouride
...
