Before the arrival of American settlers, the land where Seattle now stands was occupied by the British government.
the Duwamish people.
the Nez Perce people.
the US government.

B.

Explanation:

The question states that this is Pre-colonization, which means that the British government, nor the U.S. government, could have been there. This leaves you with B and C. The Nez Perce were more located in central Idaho, while the Duwamish people are actually nicknamed, the first people of Seattle. Hope this helps!

c it says nothing about connecting those 2 seas.