Please choose the correct answer to the question: Melissa is creating a new product to quench people's thirst. She thinks it will be more popular if it is less flat. She decides to

Answer1: add more salt to the drink Answer2: add some dissolved carbon dioxide Answer3: shake up the drink bottles before shipping them to the stores Answer4: boil the drink in a large vat

Answer format: answer1/answer2/answer3/answer4
Answer: answer2