Suppose the total cost C(x) (in dollars) to manufacture a quantity x of weed killer (in hundreds of liters) is given by the function C(x) = x3 - 3x2 + 6x + 50, where x > 0. 3) Where is C(x) decreasing? b) Where is C(x) increasing? <:> a) Select the correct choice below and ll in any answer boxes within your choice. U A- The function is decreasing on the open interval(s) (Type your answer in interval notation. Simplify your answer. Use integers or fractions for any numbers in the expression. Use a comma to separate answers as needed.) . The function is never decreasing. b) Select the correct choice below and fill in any answer boxes within your choice. '3' A- The function is increasing on the open interval(s)