Answer:
c. was one of the 10 largest cities in the world in 2005
Explanation:
Mexico city remained one of the largest cities in the world in 2005.
As the political, cultural and economic capital of one of the largest countries in Latin America, the capital city keept some sustained growth rate until 2010 and then its began to show some decrease. This can be accounted for the many people that relocated in other nearest cities in the region of central Mexico.
Based on the last census, the population of Greater Mexico City is 21.3 million, being the biggest metropolitan area of the Western Hemisphere,and the largest Spanish-speaking place in the world.
Since many people is eager to live in Mexico city there is always a permanent growth, but also many people living in that city specially highly skilled professionals and middle class sometimes relocate for improving conditions and quality of life.
The image below shows the population growth rate: