Fact 1: Apan is used for cooking food by heating food in it on a stove.

Fact 2: An oven, stove, and microwave are available to keep food warm or to heat it up.

Given the two facts above, answer the question "A what is used to keep food warm or to heat it up?" with the following options: 
- heat
 - gas
 - pan
 - foil
 - freezer
 - fur
 - bag
 - jacket


 

   pan      