I answer i would choose is C
When too much water is pumped out of an aquifer, you can make a sink hole above it, as there is now air/empty space where water used to be.
Must have more protons. Protons are positively charged, so if the atom (or in this case ion) has a net positive charge, it must have more protons (+ charge) than electrons (- charge).
The grass affects the movement by helping the water not over flow / flood
