The coastal-route theory suggests that people may have first arrived in the Americas by crossing . A.) the open Pacific on a raft and reaching the coast of South America.

B.) the land bridge but spreading south along the Pacific coast instead of moving inland.

C.) from Greenland or Iceland in large ships and traveling south along the Atlantic coast.

D.) the arctic waters by boat and traveling south along the Pacific coast.

B.) the land bridge but spreading south along the Pacific coast instead of moving inland.

Explanation:

According to this theory, humans first arrived in the Americas by crossing the kueril islands, and all the other islands across the Pacific coast of what is now Alaska, Canada, and the Pacific Northwest in the U.S, all the way to Central and South America.

This theory suggests that humans inhabited the inland regions of the Americas starting from the Pacific, which contradicts the main theory (the most accepted) that establishes that humans arrived by crossing the Bering Strait.

alaska is the answer to this

d) in the state of iowa