Answer:
Mexico City
Step-by-step explanation:
The city in Central Mexico that is located just below 20 degrees North Latitude is precisely Mexico City, the capital of the country, a sprawling metropolis of over 20 million people in its metropolitan area.
Other two important cities located just below this parallel are Toluca and Puebla, both among the top 10 largest cities in the country, and located relatively close to Mexico City.