The answer is b)<span> groundwater was overpumped
As population in Mexico City and the </span><span>San Joaquin Valley skyrocketed, the demand for water also increased.
Mexico City was once the most populated city on earth and that created a lot of burden on the cities infrastructure including the water supply.
The groundwater was over pumped leading to huge problems for millions of people.</span>
Answer:
In the 11th century CE the Awlil mines were in the hands of Takrur, but it would be the Mali Empire (1240-1645 CE), with its capital at Niani, that dominated the sub-Saharan salt trade following the collapse of the Ghana Empire.
