Finish the following sentence with the best choice: What do you need to do for the mixture to thicken?

Choices:
- When the bag is placed inside the freezer bag full of ice, you need to place the bag in the freezer.
- When the bag is placed inside the freezer bag full of ice, you need to shake the bag for 10 minutes.

Answer:
When the bag is placed inside the freezer bag full of ice, you need to shake the bag for 10 minutes.