Please choose the correct answer to the question: How do most fish get the oxygen they need to survive?

Answer1: They take in water and break it down into hydrogen and oxygen. Answer2: Using their gills, they take in oxygen that is dissolved in water. Answer3: They get their oxygen from the food they eat. Answer4: They come to the surface every few minutes to breathe air into their lungs.

Answer format: answer1/answer2/answer3/answer4