Warm water rising to the surface of the ocean and cooler water sinking
A conduction B convection C radiation

Convection is correct because of the currents that are placed when the heat comes up and the cooler liquid is going to the bottom!!!

how to make a simple air condition

in cartography, a contour line (often just called a "contour") joins points of equal elevation (height) above a given level, such as mean sea level. a contour map is a map illustrated with contour lines, for example a topographic map, which thus shows valleys and hills, and the steepness or gentleness of slopes.

explanation: