The correct answer would be D. Have a blessed week!
The population of the Philadelphia Municipal Area is 1.580 million as of 2017. As of 2018, the metropolitan area of Philadelphia has a population of 6.096 million residents.
Hope this helps!
As far as I am concerned Gao was not one of the Songhay Empire's major ones but I bet two answers should be acceptable in this question. I also think that you can include the third option from the scale represented above because <span>Algiers were quite far away on north so they couldn't be the part of the Songhay. </span>
