
The Correct choice is C
<u>Demography</u> is the study of human populations and how they grow or decline.
Gorges are narrow/skinny valleys between hills or mountains that often have a stream or river running through it. Waterfalls are rivers that stop and drop vertically into another body of water.
Hope this helped :)
Explanation:
At the center its weight is zero. Or you can argue by symmetry: if the weight is not zero, in what direction would it act?