The correct answer is - Areas at low latitudes have the warmest water because they receive the most direct sunlight.
The temperature of the surface water is directly connected to the clime of the place where the water body is located. The warmest water bodies are found in the places on the Equator and in close proximity to the Equator, thus in the low latitude parts of the world.
The reasons for this are that in the low latitudes the temperature is high throughout all of the year, and it is always summer. That is due to the more direct sunlight that this parts of the planet get. Because the sunlight falls at an angle of 90° or close to that, the sunlight is more concentrated, thus the places receive more heat, and also the water bodies are much warmer as a result of that.