The correct answer is - 100 m and 2000 m.
The thermocline represents an abrupt, sudden, rapid, drop of temperature in a body of water. In the big bodies of water, like the oceans, the thermocline is the separation line between the upper layers of the water that are warmer and more wild, and the lower layers of the water that are colder and much more calmer. In this case, the thermocline appears between 100 meters and 200 meters, and we know that because it is between these two depths were we have the biggest difference in temperature drop, which in the given situation is 13 degrees.