Answer:
Urban area.
Explanation:
according to united state census 2010
forest area land present in United States is 46% of the total area.
wet lands is about 6% of the total area.
where as urban area is around 3% of the total area present in the united states.
hence, the least area present in the united states is urban area which is about 3% of the total present area of the USA.
