On Dry Days We Tend to Have More Trouble with Static

On dry days we tend to have more trouble with static electricity buildup than on humid days. Why?

A) On humid days the strong nuclear forces are larger, so they lose fewer charges at once (get shocked) than on dry days.
B) On humid days the many water molecules in the air pick up excess charge little by little, whereas on dry days there are fewer water molecules in the air, so we accumulate charge and get discharged only when we touch something and lose more charges at once (get shocked) .
C) A charged object is always attracted or repelled by another charged object.
D) Water is a better insulator than air.