Please choose the correct answer to the question: A water company uses lab tests on the water supply before sending the water through pipes to people's homes. How do these lab tests help people?

Answer1: by adding minerals and nutrients to the water Answer2: by checking the water to make sure it is safe to drink Answer3: by filtering chemicals and organisms out of the water Answer4: by stopping harmful substances from entering the water

Answer format: answer1/answer2/answer3/answer4