Fact 1: Arefrigerator is used for keeping food fresh for a long period of time.

Fact 2: People consume foods that are cold from refrigeration.

Given the two facts above, answer the question "What used for keeping food fresh for a long period of time?" with the following options: 
- cooled
 - viruses
 - Energy
 - heat
 - Winter
 - bacteria
 - cold
 - phytoplankton


 

       cold  