You are presented with the question "What can cause a thermal conductor to become hot?" and the following answer choices: 
- exposure to ice
 - exposure to a freezer
 - Evaporation
 - exposure to the sun
 - exposure to metal
 - electricity
 - flow of electrons
 - Electrical energy

Now knowing that if a thermal conductor is exposed to a source of heat then that conductor may become hot and radiant heat is the way the sun heats the planet, choose the best answer.


 

    exposure to the sun     