Answer:
D. The surface water is colder and more salty than normal.
Explanation:
The process in which ocean water moves to the Arctic (polar region) and gets colder and saltier is thermohaline circulation.
The polar regions are extremely cold, thus making the ocean water freeze and turn into ice. When the ocean water turns into ice, it leaves salt behind. The ocean water not frozen yet absorbs this salt and becomes saltier. In chemistry, we know when we saturate or supersaturate, the density gets larger. Since we are saturating the ocean water even more with salt, the density is greater, and thus it sinks.
