How many cities are there in North America?

As of 2018, there are 19,495 incorporated cities, towns and villages in the United States. 14,768 of these have populations below 5,000. Only ten have populations above 1 million and none are above 10 million.

Explanation:

There were 19,502 incorporated places registered in the United States as of July 31, 2019. 16,410 had a population under 10,000 while, in contrast, only 10 cities had a population of one million or more. Suffice it to say, almost nothing is more idealized in the American imagination than small-town America

the answer is a. harriet tubman was a nurse on the battlefield.