9 If w'(t) is the rate of growth of a child in pounds per year, what does w'(t) dt represent? 6 O The child's weight at age 9. O The child's weight at age 6. O The change in the child's age (in years) between the ages of 6 and 9. O. The change in the child's weight (in pounds) between the ages of 6 and 9. O The child's initial weight at birth