Final answer:
The Makarov & Amundsen Basins are located on the floor of the Arctic Ocean, which is the smallest of the world's major oceans.
Step-by-step explanation:
The ocean basins mentioned, the Makarov & Amundsen Basins, are features found on the floor of the Arctic Ocean. Both basins are part of the Arctic's complex underwater geography, which includes various submarine ridges, shelves, and basins that make up its seabed. The Arctic Ocean is the smallest and shallowest of the world's five major oceans, and it is located mostly within the Arctic Circle at the northernmost part of the Earth. It is surrounded by landmasses and includes regions such as Baffin Island and the Canadian Shield.