From the chart you can teel that the most dense, coolest and saltiest waters can be found at the deepest levels of depth, in this case the deepest from the options would be located at less than 3,000 meters and it would be point C. As we know as we go depeer into the water of the ocean pressure increases and with that density of the water also increases, under normal circumstances the sunlight and sun heat is the only thing that is able to heat up the water of the ocean, so the deeper you go, the less sunlight and less sun heat is available so the waters become cooler.
