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. Given these facts, what can cause a thermal conductor to become hot among the following options:
- exposure to ice
 - exposure to a freezer
 - Evaporation
 - exposure to the sun
 - exposure to metal
 - electricity
 - flow of electrons
 - Electrical energy


 

    exposure to the sun     