The correct answer is option 1, the Atlantic Ocean. The Sargasso Sea is a region located in the North Atlantic Ocean, bounded by four currents forming a sort of "sea within a sea." It is named after the Sargassum seaweed that floats abundantly in this area. The Sargasso Sea is unique because it has no land boundaries, making it the only sea without a coastline. It is known for its calm and eerie stillness, caused by the convergence of the surrounding currents. This region is also famous for being a reproductive and feeding area for diverse marine life, including sea turtles and various fish species. The Sargasso Sea holds significant ecological value and is protected by international agreements to preserve its delicate ecosystem.