Goal: To prevent the jars from breaking when they are filled and processed with homemade dog food

Which of the following methods is more reasonable for accomplishing this goal?

OPTIONS:
- Preheat the jars by placing the jars in a pan with water and boil the water
- Preheat the jars by placing the jars in a pan with water and freezel the water
Preheat the jars by placing the jars in a pan with water and boil the water