I believe the answer is earthquakes.
Well overpopulation puts huge dent in available food supplies. This results in deforestation to make both farmland and lumber for building to house everyone. deforestation create CO2, and depletes vegetation which would have absorbed CO2
The correct answer is - C. Amu Darya.
The Karakum Desert is a desert located in Central Asia, it is a so-called ''cold desert'', which means that it has very high temperatures in the summer, but it's way below 0 degrees in winter, and it is one of the most northern deserts in the world. The Amu Darya river cuts across the desert, coming from the south-east and going in a north-west direction, Amu Darya practically splits the desert into almost two equal parts.
It’s Egypt! Trust me. I had the same question and it was right ;)
