The correct answer is B) coal.
After settlers migrated to North America, resources were used to establish housing and farm and grazing lands. The resource that was reduced because it was in the way, rather than because it was necessary for progress was coal.
Since the first number of European colonists arrived in the North American territories and founded the colony of Jamestown. Virginia, in 1607, the white Europeans had to find ways to survive and make a decent living. This colony in particular -at first- had some problems and difficulties to settle in. Indeed they needed the help of the Native Americans who taught them how to survive in the land and during harsh winter conditions. Coal was a necessary resource that was used to get heat.
The other options of the question were A) forest. B) grassland. C) water.