London dispersion forces are (permanent, temporary) while dipole-dipole forces are (permanent, temporary)

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:

dynamic equilibrium is the answer.

the answer your looking for is c).