Question

population growth during the gilded age was due in large part to
unemployment among workers.
an improved food supply.
better health care.
immigration to the united states.

Explanation:

The Gilded Age (late 19th century US) saw massive population growth driven primarily by millions of immigrants arriving from Europe and elsewhere seeking economic opportunities. Unemployment would not cause population growth, while improved food supply and better healthcare contributed to lower mortality but were not the largest driver of the era's population surge.

Answer:

D. immigration to the United States.