Final answer:
The practice of potlatch is associated with the (d) Pacific Northwest, where indigenous people would host a ceremonial feast to show generosity and redistribute wealth. The Mourning Wars were associated with the Northeast, involving conflicts among tribes such as the Iroquois.
Step-by-step explanation:
Potlatch is a ceremonial feast celebrated by the indigenous people of the Pacific Northwest Coast of Canada and the United States, which includes the territory of states like Washington and Oregon. During these events, a host demonstrates their generosity and wealth by giving gifts to attendees. This can also play a role in the redistribution of wealth within a community.
The Mourning Wars were associated with the Northeast. These were a series of conflicts among indigenous tribes like the Iroquois in what is now the northeastern United States and southeastern Canada. The Mourning Wars were partly initiated to avenge the deaths of tribal members and to capture members of other tribes to adopt into their own tribe.
Therefore, for your question, the blank space should be filled with 'Pacific Northwest' reflecting the cultural practice of potlatch.