The correct answer is option 4: Aral Sea. A landlocked sea is a sea that is entirely surrounded by land, with no direct connection to the open ocean. The Aral Sea is located between Kazakhstan and Uzbekistan in Central Asia. It was once the fourth largest lake in the world, but due to excessive irrigation and mismanagement of water resources, it has dramatically shrunk in size over the years. The Timor Sea, option 1, is a body of water in the western Pacific Ocean, bordered by Australia and East Timor. The Arafura Sea, option 2, is also in the western Pacific Ocean, between Australia and Indonesia. The Greenland Sea, option 3, is located in the Arctic Ocean, between Greenland and Iceland.