The top layer of the lake is called as

The correct answer is: B. Epilimnion

The epilimnion is the top layer of a lake or reservoir that is warmer and less dense than the water below it. It is typically well-mixed by wind and currents, and supports

most of the lake’s plant and animal life.

The thermocline is a layer of water in a lake or ocean that

separates the warmer, less dense water of the epilimnion from the colder, denser water of the hypolimnion. It is typically a few meters thick, and its depth varies with the seasons.

The hypolimnion is the bottom layer of a lake or reservoir that is colder and denser than the water above it. It is typically not well-mixed, and supports little plant or animal life.

The thermonion is not a real term.