Often before sunrise on a clear, calm, cold morning, ice (frost) can be seen on the tops of parked cars, even when the air temperature is above freezing. This condition happens because the tops of the cars are cooling by:

The correct answer is: D. Radiation

Radiation is the transfer of energy through electromagnetic waves. The sun radiates energy to the Earth, and the Earth radiates energy back to space. On a clear, calm, cold morning, the Earth’s surface radiates energy into space more quickly than it receives energy from the sun. This causes the Earth’s surface to cool. The tops of cars are exposed to the open sky, so they cool more quickly than the ground. When the air temperature is below freezing, the water vapor in the air condenses on the cold surfaces of the cars, forming frost.

Conduction is the transfer of heat between two objects that are in direct contact with each other. Convection is the transfer of heat through the movement of fluids. Latent heat is the heat that is absorbed or released when a substance changes state, such as from a liquid to a solid.

In this case, conduction, convection, and latent heat are not the main mechanisms by which the tops of cars cool. The main mechanism is radiation.