Please choose the correct solution to the question: To test baking soda to make sure it's still good.

Solution1: Add a teaspoon of baking soda to a 1/2 cup of hot water. If it doesn’t bubble, it’s time to throw it away.

Solution2: Add a teaspoon of baking soda to a 1/2 cup of cold water. If it doesn’t bubble, it’s time to throw it away.

Answer format: solution1/solution2