Find the open intervals where the function is concave upward or concave downward Find any inflection points. Select the correct choice below and, if necessary, fll in the answer box(es) to complete your choice O A. The function is concave upward on the and concave downward on interval(s) the interval(s) (Type your answers in interval notation. Use a comma to separate answers as needed) B. The function is concave upward on the 4- interval(s) The function is never concave downward. (Type your answer in interval notation. Use a comma to separate answers as needed.) OC. The function is concave downward on the interval(s) The function is never concave upward. (Type your answer in interval notation Use a comma to separate answers as needed.) O D. The function is never concave upward or downward