A new city is built in an area with a large lake. The city primarily uses the lake as a major water supply for a variety of different city needs. This becomes a concern for environmentalists. Why are they concerned?
A - Water is a non-renewable natural resource, so their supply is limited
B - This kind of a large-scale use of water supply leads to increased soil erosion
C - This kind of large-scale use of a water supply leads to increased greenhouse gases
D - Water is a renewable natural resource, but if they use it too fast, nature won't keep up
Answer: D - Water is a renewable natural resource, but if they use it too fast, nature won't keep up