Please choose the correct answer to the question: Toni got a cut on her arm while playing in a softball game. A few weeks later, the cut was healed. Which process is most responsible for repairing the cut?

Answer1: signals transported by nerve cells Answer2: exchange of oxygen in the lungs Answer3: transport of waste by blood Answer4: reproduction of skin cells

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