If you're talking about WW2, it's the battle of Stalingrad.
If it's about WW1, it would probably be Verdun.
Stress does increase the risk of disease because it alters with ones brain and nerves which can lead to deadly diseases.
The correct answer is <span>c. transported groundwater from a distance
It wasn't the first known use of wells as wells older than them were found in places like Cyprus and Egypt and Austria who were as old as 6000-8000 years before common era. It also wasn't a postindustrial system as it was used in ancient china in the expansion of trading during the silk road trading era. It only leaves C as the correct answer.</span>
