56:14 Which of the following statements is the best description of exponential behavior? A. Exponential behavior occurs when a function increases at a rate of increasing value. B. Exponential behavior occurs when a function increases at a rate of decreasing value. C. Exponential behavior occurs when a function increases or decreases at a rate proportional to its current value. D. Exponential behavior occurs when a function increases or decreases at a rate proportional to its initial value.