Which of the following statements best defines compound interest? O Interest that grows with a constant rate of change that is calculated both on money you deposit and on money you have earned in interest O Interest that grows with a variable rate of change that is earned only if you deposit money into an account every month. O Interest that grows with a variable rate of change that is calculated both on money you deposit and on money you have earned in interest. O Interest that only happens when you are in debt that grows with a constant rate of change. O Interest that grows with a variable rate of change that is earned only on the money you deposit