Final answer:
Tribes primarily inhabiting the Northeastern U.S., such as the Iroquois Confederacy, were located in the New England region. The question's correct answer is a) New England. Additionally, the practice of potlatch is associated with the Pacific Northwest, not the Northeastern region.
Step-by-step explanation:
The various Native American tribes that inhabited the Northeastern region of the early United States were both agriculturalists and hunter/gatherers. Prominent among these were the Iroquois Confederacy, which was a significant political unit in the region. This region, known as New England, was the primary home to tribes in the Northeastern U.S. Therefore, the correct answer to which region was primarily home to tribes in the Northeastern U.S. would be a) New England.
As for the practice of potlatch, it is associated with the d) Pacific Northwest region. This practice was not found among the tribes of the Northeast, the Southwest, or the Plains.