Hey there!
Your answer is B. MgCl.
This is because this isn't an actual existing compound.
Water (H₂O) and magnesium chloride (MgCl₂) are both real compounds, but the number of electrons does not line up to make MgCl possible.
Hope this helps!
I am pretty sure it is white white liquid but if I’m not right I am so sorry
The major limitation is that C) he can not definitively show what causes the difference.
It may be caused by <em>something the people are doing</em> (if so, what?) or it may be caused by <em>some environmental differences</em> or a<em> combination of both</em>.