Find the intervals on which f is increasing and the intervals on which it is decreasing. f ( x ) = - +2x3 - 4x2 Select the correct choice below and, if necessary, fill in the answer box(es) to complete your choice. A. The function is decreasing on the open interval(s) . The function is never increasing. (Simplify your answer. Use a comma to separate answers as needed. Type your answer in interval notation.) O B. The function is increasing on the open interval(s) . The function is never decreasing. (Simplify your answer. Use a comma to separate answers as needed. Type your answer in interval notation.) O C. The function is increasing on the open interval(s) and decreasing on the open interval(s). (Simplify your answers. Use a comma to separate answers as needed. Type your answers in interval notation.) O D. The function is never increasing or decreasing