The answer is:
_________________________________________________________
"an irregular boundary—specifically, an irregular coastline".
_________________________________________________________
I would say (A) because these houses was for the poor.
Tribal territories and the slave trade ranged over present-day borders. Some Native American tribes held war captives as slaves prior to and during European colonization. Some Native Americans were captured and sold by others into slavery to Europeans, while others were captured and sold by Europeans themselves. In the late 18th and 19th centuries, a small number of tribes adopted the practice of holding slaves as chattel property, holding increasing numbers of African-American slaves.
European influence greatly changed slavery used by Native Americans, as pre-contact forms of slavery were generally distinct from the form of chattel slavery developed by Europeans in North America during the colonial period. As they raided other tribes to capture slaves for sales to Europeans, they fell into destructive wars among themselves, and against Europeans.
