Answer:
a. mississippi
Step-by-step explanation:
The Mississipi River is not associated with one of the largest population centers in the world. This river is a very important river for the United States, it is the second longest river in the country, surpassed only by Missouri.
The Mississippi River rises on Lake Itasca, in Itasca State Park, in the US state of Minnesota, and runs through the states of Minnesota, Wisconsin, Iowa, Illinois, Missouri, Kentucky, Arkansas, Tennessee, Mississippi and Louisiana.