I would say it would b D. Irish moving to America during the Potato Famine, as it wasn't necessarily forced, but they went of their own free will
Because an area of land could support up to 500 times' as many people by farming as it could by hunting and gathering.
Aquifer is simply ground water and one of the best sources of quality water for irrigation and home use.
aquifer can be polluted like any other sources of water.
This can happen when pollutants such as random gas, oils,and chemicals get into the aquifer thus contaminating it.
If the ice melts, the temperature could increase.
Hope this answer helps, If you have any other questions just feel free to ask :)
