Which area was covered under the 1862 homestead act?

The answer is The Great Plains

The Homestead Act signed by the American President Abraham Lincoln, was as a form to accelerate the western territory settlement, that is to say, The Great Plains, which lies west of the Mississippi River and east of the Rocky Mountains in the U.S. and Canada.

The Act gave adult men citizens, including black men, the possibility to acquire 160 acres with the condition to pay a minimal filing fee and continuously reside for 5 years in the land.

i beleive that d is the right answer